Fixed: Mis-classification of releases as being Czech (#3378)

After the changes from PR #2948, the regex was too eager to match any
substring contain "SK", such as in "MASK". Fix by requiring word
separation around it, as was already the case with the "CZ" token.

src/NzbDrone.Core/Parser/LanguageParser.cs

@@ -13,7 +13,7 @@ namespace NzbDrone.Core.Parser
     {
         private static readonly Logger Logger = NzbDroneLogger.GetLogger(typeof(LanguageParser));
 
-        private static readonly Regex LanguageRegex = new Regex(@"(?:\W|_)(?<italian>\b(?:ita|italian)\b)|(?<german>german\b|videomann)|(?<flemish>flemish)|(?<greek>greek)|(?<french>(?:\W|_)(?:FR|VOSTFR|VO|VFF|VFQ|VF2|TRUEFRENCH)(?:\W|_))|(?<russian>\brus\b)|(?<dutch>nl\W?subs?)|(?<hungarian>\b(?:HUNDUB|HUN)\b)|(?<hebrew>\bHebDub\b)|(?<czech>\bCZ|SK\b)",
+        private static readonly Regex LanguageRegex = new Regex(@"(?:\W|_)(?<italian>\b(?:ita|italian)\b)|(?<german>german\b|videomann)|(?<flemish>flemish)|(?<greek>greek)|(?<french>(?:\W|_)(?:FR|VOSTFR|VO|VFF|VFQ|VF2|TRUEFRENCH)(?:\W|_))|(?<russian>\brus\b)|(?<dutch>nl\W?subs?)|(?<hungarian>\b(?:HUNDUB|HUN)\b)|(?<hebrew>\bHebDub\b)|(?<czech>\b(?:CZ|SK)\b)",
                                                                 RegexOptions.IgnoreCase | RegexOptions.Compiled);
 
         private static readonly Regex SubtitleLanguageRegex = new Regex(".+?[-_. ](?<iso_code>[a-z]{2,3})$", RegexOptions.Compiled | RegexOptions.IgnoreCase);