Remove apostrophe highlighting (#3)

Highlighting on apostrophes seems to cause more problems
than it solves, and it seems unlikely that it will be missed, as
it's much more common to use quotes for strings rather than
apostrophes.

Fixes: https://pagure.io/pagure/issue/5103

rpm-specfile.js

@@ -25,7 +25,6 @@ function hljsDefineRpmSpecfile(hljs) {
     contains: [
         hljs.COMMENT('%dnl'),
         hljs.HASH_COMMENT_MODE,
-        hljs.APOS_STRING_MODE,
         hljs.QUOTE_STRING_MODE,
         {
             className: "type",