tests: Fix incorrectly implicitly concatenated string in specifiers test (#946)

Author: notatallshaw

tests/test_specifiers.py

@@ -179,7 +179,7 @@ def test_specifiers_invalid(self, specifier):
             "1.0-POST1",
             "1.0-5",
             # Local version case insensitivity
-            "1.0+AbC"
+            "1.0+AbC",
             # Integer Normalization
             "1.01",
             "1.0a05",