How to disable vary User-Agent from response header in Apache - apache

Question

I have tried a few .htaccess commands like RequestHeader unset User-Agent
but it isn't working. I also removed compression to check whether it was trigerring User-Agent or not but it wasn't.
Could you tell me how to remove Vary User-Agent from my response header. I think it is there by default.
Might it be that it has to be done from cPanel & WHM. If that is the case then could you guide me on how to do it?
Or if it is to be done through .htaccess then also I need your help on how to do it.
Here's how my .htaccess currently looks like:
# ------------------------------------------------------------------------------
# | Web fonts access |
# ------------------------------------------------------------------------------
# Allow access from all domains for web fonts
<IfModule mod_headers.c>
<FilesMatch "\.(eot|otf|ttc|ttf|woff)$">
Header set Access-Control-Allow-Origin "*"
</FilesMatch>
# ------------------------------------------------------------------------------
# | Compression |
# ------------------------------------------------------------------------------
<IfModule mod_deflate.c>
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE text/javascript
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE image/x-icon
AddOutputFilterByType DEFLATE image/svg+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/x-font
AddOutputFilterByType DEFLATE application/x-font-truetype
AddOutputFilterByType DEFLATE application/x-font-ttf
AddOutputFilterByType DEFLATE application/x-font-otf
AddOutputFilterByType DEFLATE application/x-font-eot
AddOutputFilterByType DEFLATE application/x-font-woff
AddOutputFilterByType DEFLATE application/x-font-opentype
AddOutputFilterByType DEFLATE application/vnd.ms-fontobject
AddOutputFilterByType DEFLATE font/ttf
AddOutputFilterByType DEFLATE font/woff
AddOutputFilterByType DEFLATE font/eot
AddOutputFilterByType DEFLATE font/svg
AddOutputFilterByType DEFLATE font/otf
AddOutputFilterByType DEFLATE font/opentype
# For Olders Browsers Which Can't Handle Compression
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4\.0[678] no-gzip
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
</IfModule>
# ------------------------------------------------------------------------------
# | Add Expiry and Unset Pragma and ETag |
# ------------------------------------------------------------------------------
Header unset Pragma
# 1 Month for most static assets 3 months for proxies
<FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|swf)(\.gz)?$">
Header set Cache-Control "max-age=2592000, s-maxage=7776000, must-revalidate, proxy-revalidate, no-transform"
Header unset ETag
FileETag None
</FilesMatch>
# 3 Days for normal and 1 week for proxies
<filesMatch ".(css|xml|html|php)$">
Header set Cache-Control "max-age=259200, s-maxage=604800, must-revalidate, proxy-revalidate, no-transform"
Header unset ETag
FileETag None
</FilesMatch>
#-------------------------------------------------------------------------------
Any help would be greatly appreciated. Thanks in advance!