Remove use of dokku binary from git plugin

plugins/git/receive-app

@@ -1,18 +1,20 @@
 #!/usr/bin/env bash
 set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+source "$PLUGIN_AVAILABLE_PATH/git/functions"
 
-git_receive_app(){
+git_receive_app() {
   declare desc="git receive-app plugin trigger"
   local trigger="git_receive_app"
   local APP="$1"; local REV="$2"
+  local cmd="git-build"
 
   # Don't trigger git build if there is no git repository.
   if [[ ! -d "$DOKKU_ROOT/$APP/refs" ]]; then
     true
   else
     # shellcheck disable=SC2086
-    dokku git-build $APP $REV
+    git_build_cmd $cmd $APP $REV
   fi
 }