Prevent NullRef in IsPathValid for null paths

src/NzbDrone.Common/Extensions/PathExtensions.cs

@@ -138,7 +138,7 @@ namespace NzbDrone.Common.Extensions
 
         public static bool IsPathValid(this string path, PathValidationType validationType)
         {
-            if (path.ContainsInvalidPathChars() || string.IsNullOrWhiteSpace(path))
+            if (string.IsNullOrWhiteSpace(path) || path.ContainsInvalidPathChars())
             {
                 return false;
             }