fix: updated typo

[TunahanB]

Hardened an image super-resolution GUI (SRGAN/WDSR) against silent failures:

• GPU crash on CPU-only machines: Guarded with device check
• Dead None-check after dereference: Moved guard before np.array()/cvtColor
• float32 JPEG corruption: OpenCV misinterprets float range, swapped to uint8
• Grayscale/RGBA image crashes: Added .convert("RGB")
• Cancel-save writing phantom .jpg: Added empty-path guard
• Private TF API (tensorflow.python.keras): Migrated to public tensorflow.keras
• Missing weight files: Explicit isfile checks with actionable errors instead of opaque tracebacks
• Hardcoded paths: Auto-create processimage/ directories before writes