Prevent another macro from storing pointers to dotconf's strings.
Prevent another macro from storing pointers to dotconf's strings.

The SPEECHD_OPTION_CB_STR_M macro was doing the same thing as
some other macros in configuration.c.  It was storing pointers
to data owned by dotconf in a global structure.
I missed it in my previous patch to fix this bug.

razr/opentts,razr/opentts,razr/opentts,razr/opentts