revert xformers

launch.py

@@ -228,7 +228,7 @@ def prepare_environment():
     torch_command = os.environ.get('TORCH_COMMAND', "pip install torch torchvision --extra-index-url https://download.pytorch.org/whl/cu118")
     requirements_file = os.environ.get('REQS_FILE', "requirements_versions.txt")
 
-    xformers_package = os.environ.get('XFORMERS_PACKAGE', 'xformers==0.0.18')
+    xformers_package = os.environ.get('XFORMERS_PACKAGE', 'xformers==0.0.17')
     gfpgan_package = os.environ.get('GFPGAN_PACKAGE', "git+https://github.com/TencentARC/GFPGAN.git@8d2447a2d918f8eba5a4a01463fd48e45126a379")
     clip_package = os.environ.get('CLIP_PACKAGE', "git+https://github.com/openai/CLIP.git@d50d76daa670286dd6cacf3bcd80b5e4823fc8e1")
     openclip_package = os.environ.get('OPENCLIP_PACKAGE', "git+https://github.com/mlfoundations/open_clip.git@bb6e834e9c70d9c27d0dc3ecedeebeaeb1ffad6b")