Removing client-side check for whitespace in finding by class name

This check is handled by the atoms, and will throw the proper error. There
is no need to check this on the local end, and will ensure consistent
behavior between language bindings.

dotnet/src/webdriver/By.cs

@@ -221,11 +221,6 @@ public static By ClassName(string classNameToFind)
                 throw new ArgumentNullException("classNameToFind", "Cannot find elements when the class name expression is null.");
             }
 
-            if (new Regex(".*\\s+.*").IsMatch(classNameToFind))
-            {
-                throw new IllegalLocatorException("Compound class names are not supported. Consider searching for one class name and filtering the results.");
-            }
-
             By by = new By();
             by.findElementMethod =
                 (ISearchContext context) => ((IFindsByClassName)context).FindElementByClassName(classNameToFind);