resourceloader: Remove Grade C sniffs for WebOS <=1.4 and SymbianOS

resourceloader: Remove Grade C sniffs for WebOS <=1.4 and SymbianOS

Added originally in c46fc745a9de7201e based on the support document for
jQuery Mobile 1.3, via <https://jquerymobile.com/browser-support/1.3/>.

These have been obsolete since T102318 because startup.js is now a feature
test, with UA-snifs only for browsers that both *do* have all Grade A
capabilities for which we still want to disable the JS pipeline.

* Palm WebOS: Upstream jQuery 1.x allegedly worked fine on WebOS 1.4+.
  Not sure why we excluded WebOS <= 1.4, looks like that should have
  been <= 1.3 instead.
  If it doesn't have the neccecary HTML5/ES5/CSS3 features,
  it will remain in Grade C without a sniff. Otherwise, it's probably
  fine to enable. Either way, not officially supported (Grade X).

  Usage on WMF wikis is presumed less than 0.1% as neiter Palm nor
  WebOS show up on https://analytics.wikimedia.org/.

  The example UAs mention WebKit/525 and WebKit/532 which
  correlate with Safari 3.x and Safari 4.x, which we know
  doesn't pass the feature test.

* Symbian:
  The example UAs mention WebKit/413 which corelates with Safari 2,
  which we know doesn't pass the feature test.

Change-Id: I62a83e3b4967f309739095d9c73650f9859ee856