ZODB3: Switch transaction 1.1.1 -> 1.6.1

NEO/ZODB3 was using transaction 1.1.1, but ZODB3 was fixed to follow transaction 1.6.1 in 2016:

https://github.com/zopefoundation/ZODB/commit/d8409616

Actually ZODB3 tests fail with transaction 1.1.1

https://erp5.nexedi.net/test_result_module/20201123-60855473/6

component/ZODB/buildout.cfg

@@ -100,7 +100,7 @@ setup   = ${ZODB3-repository:location}
 egg     = ZODB3
 
 egg_versions =
-  transaction = 1.1.1
+  transaction = 1.6.1
   zdaemon = 2.0.7
 
 [ZODB3-repository]