tool_getparam: fix memory leak in parse_args

Prior to this change in Windows Unicode builds most parsed options would
not be freed.

Found using _CrtDumpMemoryLeaks().

Ref: https://github.com/curl/curl/issues/5545

src/tool_getparam.c

@@ -2302,6 +2302,8 @@ ParameterError parse_args(struct GlobalConfig *global, int argc,
       result = getparameter("--url", orig_opt, &used, global,
                             config);
     }
+
+    curlx_unicodefree(orig_opt);
   }
 
   if(result && result != PARAM_HELP_REQUESTED &&