fix bug: multisite-convert option always runs

Author: devosc

bin/docker-wp

@@ -72,7 +72,7 @@ for ((i=0; i < "$#"; ++i)); do
     esac
 done
 
-if ${multisite} ; then
+if [[ "${multisite}" = "true" ]] ; then
     multisite_convert "${directory}"
     exit
 fi