only load libs when necessary

fooocus_version.py

@@ -1 +1 @@
-version = '2.1.794'
+version = '2.1.795'

modules/async_worker.py

@@ -28,12 +28,11 @@ def worker():
     import modules.constants as constants
     import modules.advanced_parameters as advanced_parameters
     import fooocus_extras.ip_adapter as ip_adapter
-    import fooocus_extras.face_crop
 
     from modules.sdxl_styles import apply_style, apply_wildcards, fooocus_expansion
     from modules.private_logger import log
     from modules.expansion import safe_str
-    from modules.util import join_prompts, remove_empty_str, HWC3, resize_image, \
+    from modules.util import remove_empty_str, HWC3, resize_image, \
         get_image_shape_ceil, set_image_shape_ceil, get_shape_ceil, resample_image
     from modules.upscaler import perform_upscale
 
@@ -545,6 +544,8 @@ def worker():
                     return
             for task in cn_tasks[flags.cn_ip_face]:
                 cn_img, cn_stop, cn_weight = task
+
+                import fooocus_extras.face_crop
                 cn_img = fooocus_extras.face_crop.crop_image(HWC3(cn_img))
 
                 # https://github.com/tencent-ailab/IP-Adapter/blob/d580c50a291566bbf9fc7ac0f760506607297e6d/README.md?plain=1#L75