restore tests to passing in php7.0

Author: SergeyTsalkov

simpletest/WalkTest.php

@@ -36,7 +36,7 @@ function test_2_walk_empty() {
 
   function test_3_walk_insert() {
     // old mysql pdo driver chokes when you try to 
-    if ($this->db_type == 'mysql' && phpversion() < '7.0') return;
+    if ($this->db_type == 'mysql' && phpversion() < '7.4') return;
 
     $Walk = DB::queryWalk("INSERT INTO profile (id) VALUES (100)");