Removed Django 1.5 upgrade hints for {% url %} tag.

Refs #19280 and Refs #19392.

django/template/defaulttags.py

@@ -434,10 +434,6 @@ class URLNode(Node):
 
         view_name = self.view_name.resolve(context)
 
-        if not view_name:
-            raise NoReverseMatch("'url' requires a non-empty first argument. "
-                "The syntax changed in Django 1.5, see the docs.")
-
         # Try to look up the URL twice: once given the view name, and again
         # relative to what we guess is the "main" app. If they both fail,
         # re-raise the NoReverseMatch unless we're using the
@@ -1345,12 +1341,7 @@ def url(parser, token):
     if len(bits) < 2:
         raise TemplateSyntaxError("'%s' takes at least one argument"
                                   " (path to a view)" % bits[0])
-    try:
-        viewname = parser.compile_filter(bits[1])
-    except TemplateSyntaxError as exc:
-        exc.args = (exc.args[0] + ". "
-                "The syntax of 'url' changed in Django 1.5, see the docs."),
-        raise
+    viewname = parser.compile_filter(bits[1])
     args = []
     kwargs = {}
     asvar = None