WI: Don't explode when user uploads image without a save

This is a band-aid on an underlying problem: there is no save directory
to put blobs like images in before the user saves the game. The way
forward is probably to have an in-memory (no disk, Colab privacy (thats
kind of an oxymoron)) folder or something. I want to expand the data
storage functionality into an api in the future so devs can seamlessly
do something like:

Data.get_file_contents("image/blahblah.png")

and they won't have to actually worry about stuff like this

aiserver.py

@@ -6715,11 +6715,18 @@ def UI_2_set_wi_image(uid):
         except FileNotFoundError:
             pass
     else:
+        try:
             # Otherwise assign image
             with open(path, "wb") as file:
                 file.write(data)
+        except FileNotFoundError:
+            show_error_notification(
+                "Unable to write image",
+                "Please save the game before uploading images."
+            )
+            return ":(", 500
     koboldai_vars.gamesaved = False
-    return ":)"
+    return ":)", 200
 
 @app.route("/get_wi_image/<int(signed=True):uid>", methods=["GET"])
 @require_allowed_ip