dist: Add back arch in x64 linux AppImage (#1754)

With the recent versions of `electron-builder`, the generated AppImage
file for x64 architectures does not have `x86_64` in its name like it
used to.
We need this part in the file name for the nuts server to find it when
users want to download the app from our website.

electron-builder.yml

@@ -20,6 +20,13 @@ asarUnpack:
 - gui/scripts/**
 directories:
   buildResources: gui/assets
+mac:
+  hardenedRuntime: true
+  entitlements: './build/entitlements.mac.inherit.plist'
+  category: public.app-category.productivity
+  target:
+  - dmg
+  - zip
 dmg:
   contents:
     - x: 110
@@ -31,13 +38,6 @@ dmg:
 win:
   target:
   - nsis
-mac:
-  hardenedRuntime: true
-  entitlements: './build/entitlements.mac.inherit.plist'
-  category: public.app-category.productivity
-  target:
-  - dmg
-  - zip
 linux:
   target:
   - AppImage
@@ -50,3 +50,5 @@ linux:
     anytime with the mobile application and share them with the world or just your
     friends and colleagues. You can host your own Cozy Cloud, and or use the hosting
     services. Your freedom to chose is why you can trust us.
+appImage:
+  artifactName: 'Cozy-Drive-${version}-${arch}.${ext}'