functions: only update file-permissions when needed

Modifying the permissions only for files that have wrong permissions will speed up container start. A welcome sideeffect is no change of ctime, which helps to prevent not needed external backups.

assets/runtime/functions

@@ -803,8 +803,8 @@ initialize_datadir() {
     if [ ${REDMINE_DATA_DIR} = ${dir} ]; then
       mkdir -p ${dir}
     fi
-    chmod -R u+rw,go+r ${dir}
-    chown -R ${REDMINE_USER}: ${dir}
+    find ${dir} \! -perm -u=wr,go=r -print0 | xargs -0 -r chmod u+rw,go+r
+    find ${dir} \! -user ${REDMINE_USER} -print0 | xargs -0 -r chown ${REDMINE_USER}:
   done
 }