consolidate email validation checks

include/text.php

@@ -1042,19 +1042,6 @@ function searchbox($s,$id='search-box',$url='/search',$save = false) {
 	));
 }
 
-function valid_email_regex($x){
-	if(preg_match('/^[_a-zA-Z0-9\-\+]+(\.[_a-zA-Z0-9\-\+]+)*@[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)+$/',$x))
-		return true;
-	return false;
-}
-
-function valid_email($x){
-	if(get_config('system','disable_email_validation'))
-		return true;
-
-	return valid_email_regex($x);
-}
-
 /**
  * @brief Replace naked text hyperlink with HTML formatted hyperlink.
  *