Switch source for dictionaries

cgit.freedesktop.org has been down for weeks without explanation

Author: guyer

.azure/pipelines.yml

@@ -41,8 +41,11 @@ stages:
           pip_packages: pyspelling
 
       - bash: |
-          wget -O en_US.aff  https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.aff?id=a4473e06b56bfe35187e302754f6baaa8d75e54f
-          wget -O en_US.dic https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.dic?id=a4473e06b56bfe35187e302754f6baaa8d75e54f
+          # cgit.freedesktop.org has been down for weeks without explanation
+          # wget -O en_US.aff  https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.aff?id=a4473e06b56bfe35187e302754f6baaa8d75e54f
+          # wget -O en_US.dic https://cgit.freedesktop.org/libreoffice/dictionaries/plain/en/en_US.dic?id=a4473e06b56bfe35187e302754f6baaa8d75e54f
+          wget -O en_US.aff https://raw.githubusercontent.com/freedesktop-unofficial-mirror/libreoffice__dictionaries/master/en/en_US.aff
+          wget -O en_US.dic https://raw.githubusercontent.com/freedesktop-unofficial-mirror/libreoffice__dictionaries/master/en/en_US.dic
         displayName: Obtain dictionaries
 
       - bash: |