return base url when not None (#643)

Author: jasonpraful

src/cohere/client.py

@@ -121,8 +121,10 @@ async def _async_wrapped(*args, **kwargs):
 
 
 def fix_base_url(base_url: typing.Optional[str]) -> typing.Optional[str]:
-    if base_url is not None and ("cohere.com" in base_url or "cohere.ai" in base_url):
-        return base_url.replace("/v1", "")
+    if base_url is not None:
+        if "cohere.com" in base_url or "cohere.ai" in base_url:
+            return base_url.replace("/v1", "")
+        return base_url
     return None