fetchrepoproject: fix a bug that was there since bef6bef0d2ce2ef7cfaa3e9f1eac2cdc793560c4

pkgs/build-support/fetchrepoproject/default.nix

···
     ${optionalString (local_manifests != []) ''
       mkdir .repo/local_manifests
       for local_manifest in ${concatMapStringsSep " " toString local_manifests}; do
-        cp $local_manifest .repo/local_manifests/$(stripHash $local_manifest; echo $strippedName)
+        cp $local_manifest .repo/local_manifests/$(stripHash $local_manifest)
       done
     ''}