Fix multi-arch

Author: Corentin ARNOULD

.github/workflows/BuildImage.yml

@@ -15,7 +15,7 @@ env:
   BASEIMAGE: "openssh-server" #replace
   MODNAME: "trusted-ca" #replace
   MOD_VERSION: ${{ inputs.mod_version }} #don't modify
-  MULTI_ARCH: "true" #set to false if not needed
+  MULTI_ARCH: "false" #set to false if not needed
 
 jobs:
   set-vars: