Fix URLField to allow numbers in top level domain

Add a custom regex to URLField that allows numbers to be present in the
top level domain, e.g. https://towerhost.org42

Set by variable allow_numbers_in_top_level_domain in URLField __init__,
and is set to True by default. If set to False, it will use the regex
specified in the built-in django URLValidator class.

This solution was originally implemented in LDAPServerURIField, but is
now implemented in URLField to support this behavior more generally. The
changes in LDAPServerURIField are longer needed and have been removed in
this commit.

Adds unit testing to make sure URLField changes handle regex input
and settings correctly.

awx/conf/tests/unit/test_fields.py

@@ -1,7 +1,7 @@
 import pytest
 
 from rest_framework.fields import ValidationError
-from awx.conf.fields import StringListBooleanField, StringListPathField, ListTuplesField
+from awx.conf.fields import StringListBooleanField, StringListPathField, ListTuplesField, URLField
 
 
 class TestStringListBooleanField():
@@ -62,7 +62,7 @@ class TestListTuplesField():
     FIELD_VALUES = [
         ([('a', 'b'), ('abc', '123')], [("a", "b"), ("abc", "123")]),
     ]
-    
+
     FIELD_VALUES_INVALID = [
         ("abc", type("abc")),
         ([('a', 'b', 'c'), ('abc', '123', '456')], type(('a',))),
@@ -130,3 +130,25 @@ class TestStringListPathField():
             field.to_internal_value([value])
         assert e.value.detail[0] == "{} is not a valid path choice.".format(value)
 
+
+class TestURLField():
+    regex = "^https://www.example.org$"
+
+    @pytest.mark.parametrize("url,schemes,regex, allow_numbers_in_top_level_domain, expect_no_error",[
+        ("ldap://www.example.org42", "ldap", None, True, True),
+        ("https://www.example.org42", "https", None, False, False),
+        ("https://www.example.org", None,  regex, None, True),
+        ("https://www.example3.org", None, regex, None, False),
+        ("ftp://www.example.org", "https", None, None, False)
+    ])
+    def test_urls(self, url, schemes, regex, allow_numbers_in_top_level_domain, expect_no_error):
+        kwargs = {}
+        kwargs.setdefault("allow_numbers_in_top_level_domain", allow_numbers_in_top_level_domain)
+        kwargs.setdefault("schemes", schemes)
+        kwargs.setdefault("regex", regex)
+        field = URLField(**kwargs)
+        if expect_no_error:
+            field.run_validators(url)
+        else:
+            with pytest.raises(ValidationError):
+                field.run_validators(url)