Fix WeKan Snap Candidate v7.71 build. There was old version number.

Thanks to xet7 !

snapcraft.yaml

@@ -170,9 +170,9 @@ parts:
             # Cleanup
             mkdir .build
             cd .build
-            wget https://github.com/wekan/wekan/releases/download/v7.70/wekan-7.70-amd64.zip
-            unzip wekan-7.70-amd64.zip
-            rm wekan-7.70-amd64.zip
+            wget https://github.com/wekan/wekan/releases/download/v7.71/wekan-7.71-amd64.zip
+            unzip wekan-7.71-amd64.zip
+            rm wekan-7.71-amd64.zip
             cd ..
             ##cd .build/bundle
             ##find . -type d -name '*-garbage*' | xargs rm -rf