kamailio.cfg: load corex module to get same cfg api as so far

etc/kamailio.cfg

@@ -216,6 +216,7 @@ loadmodule "db_mysql.so"
 
 loadmodule "mi_fifo.so"
 loadmodule "kex.so"
+loadmodule "corex.so"
 loadmodule "tm.so"
 loadmodule "tmx.so"
 loadmodule "sl.so"