Fix validate_executable behavior (#1915)

Validate orca executable only if server_url is not provided

Author: Alexander

Diff for: packages/python/plotly/plotly/io/_orca.py

@@ -1384,11 +1384,10 @@ def ensure_server():
 """
         )
 
-    # Validate orca executable
-    if status.state == "unvalidated":
-        validate_executable()
-
     if not config.server_url:
+        # Validate orca executable only if server_url is not provided
+        if status.state == "unvalidated":
+            validate_executable()
         # Acquire lock to make sure that we keep the properties of orca_state
         # consistent across threads
         with orca_lock: