Fix issue with strip_prefixes

Author: BVMiko

Diff for: aws_lambda_powertools/event_handler/api_gateway.py

@@ -546,6 +546,8 @@ def _remove_prefix(self, path: str) -> str:
             return path
 
         for prefix in self._strip_prefixes:
+            if path == prefix:
+                return "/"
             if self._path_starts_with(path, prefix):
                 return path[len(prefix) :]