fix image attachment with new cdn

packages/stream_chat_flutter/example/ios/Runner.xcodeproj/project.xcworkspace/contents.xcworkspacedata

@@ -2,6 +2,6 @@
 <Workspace
    version = "1.0">
    <FileRef
-      location = "group:Runner.xcodeproj">
+      location = "self:">
    </FileRef>
 </Workspace>

packages/stream_chat_flutter/lib/src/attachment/image_attachment.dart

@@ -63,8 +63,8 @@ class ImageAttachment extends AttachmentWidget {
         if (imageUri.host == 'stream-io-cdn.com') {
           imageUri = imageUri.replace(queryParameters: {
             ...imageUri.queryParameters,
-            'height': '500',
+            'h': '500',
-            'width': '500',
+            'w': '500',
             'crop': 'center',
             'resize': 'crop',
           });