Fix restartDNS returning code 1 even when it worked

If stdout was not a terminal (the `-t 1` check), `restartDNS` would
return code 1 in the success case. This caused the API to fail whenever
it tried to restart the DNS server.

Signed-off-by: Mcat12 <newtoncat12@yahoo.com>

pihole

@@ -134,9 +134,11 @@ restartDNS() {
 
   if [[ "${status}" -eq 0 ]]; then
     [[ -t 1 ]] && echo -e "${OVER}  ${TICK} ${str}"
+    return 0
   else
     [[ ! -t 1 ]] && local OVER=""
     echo -e "${OVER}  ${CROSS} ${output}"
+    return 1
   fi
 }