Issue 6823 - Remove unnecessary usage of /u flag

lib/common.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 131 matching lines @@
       // If we're already within a parenthesis, close the scope.
       if (currentScope == ")")
         scope.pop();
     }
     else if (!currentScope)
     {
       // At the top level (not within any scope), count the whitespace if we've
       // encountered it. Otherwise if we've hit one of the combinators,
       // terminate here; otherwise if we've hit a non-colon character,
       // terminate here.
-      if (/\s/u.test(character))
+      if (/\s/.test(character))
       {
         whitespace++;
       }
       else if ((character == ">" || character == "+" || character == "~") ||
                (whitespace > 0 && character != ":"))
       {
         break;
       }
     }
 
@@ skipping 33 matching lines @@
     // Note that the first group in the regular expression is optional. If it
     // doesn't match (e.g. "#foo::nth-child(1)"), type will be an empty string.
     qualifiedSelector += sub.substr(0, index) + type + qualifier + rest;
   }
 
   // Remove the initial comma and space.
   return qualifiedSelector.substr(2);
 }
 
 exports.qualifySelector = qualifySelector;