Execute pihole through wrapper

All different exec() calls basically just calls sudo pihole,
with various different syntaxes. Using a wrapper function
allows sanitization of arguments for better safety.

Signed-off-by: Samu Voutilainen <smar@smar.fi>

scripts/pi-hole/php/teleporter.php

@@ -439,7 +439,7 @@ if(isset($_POST["action"]))
 
 		if($importedsomething)
 		{
-			exec("sudo pihole restartdns reload");
+			pihole_execute("restartdns reload");
 		}
 
 		unlink($fullfilename);