Merge branch 'fix' into 'master'

rm imports.yml & projects/imports.yml

See merge request codechina/mirrors-settings!572

imports.yml

-group:
-  name: PacktPublishing
-  descripition: 'PacktPublishing book'
-  projects:
-    - name: Mastering-OpenCV-4-with-Python
-      description: 'Mastering-OpenCV-4-with-Python'
-      mirrorRelease: false
-      topic: 'Mastering-OpenCV-4-with-Python'

projects/imports.yml

----
-group:
-  name: 'imports.yml'
-  description: ''
-  projects:
-  
\ No newline at end of file