fix code cleanup mistakes

core/Driver/SQL/Query/Delete.class.php

@@ -21,7 +21,7 @@ class Delete extends Query {
     return $this;
   }
 
-  public function execute() {
+  public function execute(): bool {
     return $this->sql->executeDelete($this);
   }
 

core/Driver/SQL/Query/Query.class.php

@@ -19,6 +19,7 @@ abstract class Query {
     return $this;
   }
 
-  public abstract function execute(): bool;
+  // can actually return bool|array (depending on success and query type)
+  public abstract function execute();
 
 }

core/Driver/SQL/Query/Select.class.php

@@ -80,7 +80,7 @@ class Select extends Query {
     return $this;
   }
 
-  public function execute(): bool {
+  public function execute() {
     return $this->sql->executeSelect($this);
   }
 

core/Driver/SQL/Query/Update.class.php

@@ -28,7 +28,7 @@ class Update extends Query {
     return $this;
   }
 
-  public function execute(): bool {
+  public function execute() {
     return $this->sql->executeUpdate($this);
   }