Fixed incorrect ownership semantics on URL caused a crash under non-cow strings.

config.js

@@ -81,7 +81,7 @@
 		"default_skin" : "skin1",
 		 "paths" : [ "./" ],
 		 //"skins" : [ "skin3" ],
-		 "auto_reload" : true
+		 //"auto_reload" : true
 	},
 	"cache" : {
 		"backend" : "thread_shared",

url_dispatcher.cpp

@@ -23,7 +23,7 @@ namespace cppcms {
 			{
 			}
 
-			bool matches(std::string path)
+			bool matches(std::string const &path)
 			{
 				return boost::regex_match(path.c_str(),match_,expr_);
 			}