Only return an executor to the pool once

The executor was being returned to the pool twice, which was resulting in nil interface{} errors when creating new executors concurrently, as the transaction would not be set properly.

db/db.go

@@ -223,8 +223,6 @@ func Process(fib *fibre.Context, ast *sql.Query, vars map[string]interface{}) (o
 
 	executor := newExecutor()
 
-	defer executor.reset()
-
 	go executor.execute(ctx, ast)
 
 	// Wait for all of the processed queries to

db/executor.go

@@ -47,13 +47,6 @@ func newExecutor() (e *executor) {
 
 }
 
-func (e *executor) reset() {
-
-	e.send = nil
-	executorPool.Put(e)
-
-}
-
 func (e *executor) execute(ctx context.Context, ast *sql.Query) {
 
 	var err error