OTWO-1489 Added a validation for SVN Repo URL if empty

Author: rapbhan

lib/scm/adapters/svn/validation.rb

@@ -26,6 +26,7 @@ def validate_username
 
 		# If the URL is a simple directory path, make sure it is prefixed by file://
 		def path_to_file_url(path)
+			return nil if path.blank?
 			url =~ /:\/\// ? url : 'file://' + File.expand_path(path)
 		end