Fix remove files (#355)

Co-authored-by: Omar Al-Ithawi <[email protected]>

pbxproj/pbxextensions/ProjectFiles.py

@@ -345,7 +345,7 @@ def remove_file_by_id(self, file_id, target_name=None):
             for build_file_id in filter(lambda x: x in self.objects, build_phase.files):
                 build_file = self.objects[build_file_id]
 
-                if build_file.fileRef == file_ref.get_id():
+                if hasattr(build_file, 'fileRef') and build_file.fileRef == file_ref.get_id():
                     # remove the build file from the phase
                     build_phase.remove_build_file(build_file)
 
@@ -355,7 +355,8 @@ def remove_file_by_id(self, file_id, target_name=None):
                 target.remove_build_phase(build_phase)
 
         # remove it iff it's removed from all targets or no build file reference it
-        if len([1 for x in self.objects.get_objects_in_section('PBXBuildFile') if x.fileRef == file_ref.get_id()]) != 0:
+        if len([1 for x in self.objects.get_objects_in_section('PBXBuildFile') if
+                hasattr(x, 'fileRef') and x.fileRef == file_ref.get_id()]) != 0:
             return True
 
         # remove the file from any groups if there is no reference from any target