Fixed: OSX version detection

ref sonarr/4113 (not a fix, just partially)

(cherry picked from commit 026af222297d1d90d824e077e989ffd146bb5016)

src/NzbDrone.Mono/EnvironmentInfo/VersionAdapters/MacOsVersionAdapter.cs

@@ -37,8 +37,8 @@ namespace NzbDrone.Mono.EnvironmentInfo.VersionAdapters
             var allFiles = _diskProvider.GetFiles(PLIST_DIR, SearchOption.TopDirectoryOnly);
 
             var versionFile = allFiles.SingleOrDefault(c =>
-                c.EndsWith("SystemVersion.plist") ||
+                c.EndsWith("/SystemVersion.plist") ||
-                c.EndsWith("ServerVersion.plist"));
+                c.EndsWith("/ServerVersion.plist"));
 
             if (string.IsNullOrWhiteSpace(versionFile))
             {