Fix hang in mapproxy rendering due to PIL quantize deadlock on osx by disabling quantization

no-quant.diff

diff --git a/mapproxy/image/__init__.py b/mapproxy/image/__init__.py
index b5bb73b..0c6c6ac 100644
--- a/mapproxy/image/__init__.py
+++ b/mapproxy/image/__init__.py
@@ -282,22 +282,6 @@ def img_to_buf(img, image_opts):
     return buf
 
 def quantize(img, colors=256, alpha=False, defaults=None, quantizer=None):
-    if hasattr(Image, 'FASTOCTREE') and quantizer in (None, 'fastoctree'):
-        if not alpha:
-            img = img.convert('RGB')
-        img = img.quantize(colors, Image.FASTOCTREE)
-    else:
-        if alpha and img.mode == 'RGBA':
-            img.load() # split might fail if image is not loaded
-            alpha = img.split()[3]
-            img = img.convert('RGB').convert('P', palette=Image.ADAPTIVE, colors=colors-1)
-            mask = Image.eval(alpha, lambda a: 255 if a <=128 else 0)
-            img.paste(255, mask)
-            if defaults is not None:
-                defaults['transparency'] = 255
-        else:
-            img = img.convert('RGB').convert('P', palette=Image.ADAPTIVE, colors=colors)
-
     return img
 
 
diff --git a/mapproxy/platform/image.py b/mapproxy/platform/image.py
index ed725ca..f1d5eb3 100644
--- a/mapproxy/platform/image.py
+++ b/mapproxy/platform/image.py
@@ -50,21 +50,5 @@ def require_alpha_composite_support():
         raise ImportError('Pillow required for alpha_composite support')
 
 def quantize_pil(img, colors=256, alpha=False, defaults=None):
-    if hasattr(Image, 'FASTOCTREE'):
-        if not alpha:
-            img = img.convert('RGB')
-        img = img.quantize(colors, Image.FASTOCTREE)
-    else:
-        if alpha:
-            img.load() # split might fail if image is not loaded
-            alpha = img.split()[3]
-            img = img.convert('RGB').convert('P', palette=Image.ADAPTIVE, colors=colors-1)
-            mask = Image.eval(alpha, lambda a: 255 if a <=128 else 0)
-            img.paste(255, mask)
-            if defaults is not None:
-                defaults['transparency'] = 255
-        else:
-            img = img.convert('RGB').convert('P', palette=Image.ADAPTIVE, colors=colors)
-       
     return img
 quantize = quantize_pil
\ No newline at end of file