unwrap the adapter before checking its instance #1697

Job	Run time
Coding Standard & Static Analysis	25s
testsuite (7.4, sqlite)	31s
testsuite (8.2, sqlite)	36s
testsuite (7.4, mysql)	58s
testsuite (7.4, sqlite, prefer-lowest)	43s
testsuite (8.2, pgsql)	46s
testsuite (7.4, pgsql)	56s
testsuite (8.2, mysql)	1m 2s
	5m 57s

Provide feedback