dbtest:demarshal() - Assert that the message is iterable, or things will go really bad down the line
dbtest:demarshal() - Assert that the message is iterable, or things will go really bad down the line

Fixes static-scan warnings of this kind:

../../../dbind/dbtest.c:83:18: warning: The left operand of '==' is a garbage value [core.UndefinedBinaryOperatorResult]
    g_assert (v2 == 42);
              ~~ ^

GNOME/at-spi2-core,GNOME/at-spi2-core,GNOME/at-spi2-core