test: update test-run

Fix test_run:cmd('set variable ...') for string values (PR #146). It is
needed for enabling the use_unix_sockets_iproto option.

test-run @ 59bae401

-Subproject commit acf546a35d6d92abcfa3eda75a7b94f6f2e86691
+Subproject commit 59bae401fe7ef9dbb3d958a6c5d9c0a97746ed82