test_common.h: handle Check versions < 0.11
test_common.h: handle Check versions < 0.11

The nicer assertion macros are relatively recent; add a compatibility
shim for systems that don't have a bleeding-edge Check. (Ubuntu 16.04
ships with 0.10.0, for instance.)

icing/mod_md,icing/mod_md,icing/mod_md,icing/mod_md,icing/mod_md