sophia: a post merge fix

test/sophia/transaction.result

@@ -279,3 +279,22 @@ a:drop()
 b:drop()
 ---
 ...
+-- ensure findByKey works in empty transaction context
+space = box.schema.space.create('test', { engine = 'sophia' })
+---
+...
+index = space:create_index('primary', { type = 'tree', parts = {1, 'num'} })
+---
+...
+box.begin()
+---
+...
+space:get({0})
+---
+...
+box.rollback()
+---
+...
+space:drop()
+---
+...