message: Enable etag, allow more service-worker caching
diff: @@ -813,11 +813,11 @@ AddEncoding br .br
  # https://tools.ietf.org/html/rfc7232#section-2.3
  # `FileETag None` doesn't work in all cases.
  -<IfModule mod_headers.c>
  - Header unset ETag
  -</IfModule>
  +#<IfModule mod_headers.c>
  +# Header unset ETag
  +#</IfModule>
  -FileETag None
  +#FileETag None
  # ----------------------------------------------------------------------
  # | Expires headers |
  @@ -970,10 +970,9 @@ FileETag None
  # Do not cache the service worker!
  <FilesMatch "service-worker\.js(\.(gz|br))?">
  - FileETag None
  <IfModule mod_headers.c>
  - Header unset ETag
  - Header set Cache-Control "max-age=0, s-maxage=86400, no-cache, no-store, must-revalidate"
  + # no-cache = revalidate with the server before using
  + Header set Cache-Control "max-age=0, s-maxage=86400, no-cache"
  Header set Pragma "no-cache"
  Header unset Expires
  </IfModule>
  @@ -982,9 +981,7 @@ FileETag None
  # Do not cache html
  <FilesMatch "\.html(\.(gz|br))?">
  - FileETag None
  <IfModule mod_headers.c>
  - Header unset ETag
  Header set Cache-Control "max-age=0, s-maxage=<%= $DIM_FLAVOR === 'beta' ? 0 : 300 %>"
  Header unset Expires
  </IfModule>
  @@ -993,9 +990,7 @@ FileETag None
  # Cache version.json for only 15 minutes
  <FilesMatch "version\.json(\.(gz|br))?">
  - FileETag None
  <IfModule mod_headers.c>
  - Header unset ETag
  Header set Cache-Control "max-age=900, s-maxage=86400"
  Header unset Expires
  </IfModule>
  @@ -1004,9 +999,7 @@ FileETag None
  # Cache namifest
  <FilesMatch "manifest-webapp">
  - FileETag None
  <IfModule mod_headers.c>
  - Header unset ETag
  Header set Cache-Control "max-age=900, s-maxage=86400"
  Header set Vary "User-Agent"
  Header unset Expires
  