Do not attempt to create a ROM directory on SD2 if SD2 isn't mounted

Author: julkwiec

RomM/filesystem.py

@@ -54,7 +54,7 @@ def __init__(self) -> None:
             self._sd1_roms_storage_path = os.environ.get("ROMS_STORAGE_PATH", base_path)
 
         # Ensure the ROMs storage path exists on SD2 if SD2 is present
-        if self._sd2_roms_storage_path and os.path.exists(
+        if self._sd2_roms_storage_path and sd2_root_path and os.path.exists(
             sd2_root_path
         ) and not os.path.exists(
             self._sd2_roms_storage_path