[tests] disable test_mod_ssi in cmake (temporary)
[tests] disable test_mod_ssi in cmake (temporary)

disable test_mod_ssi in cmake (temporary) until include paths updated
or dependency added for the generated ssi parser header and impl

lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4