etc: kamailio.cfg - use enable_sctp instead of disable_sctp

- be coherent with tls variant

etc/kamailio.cfg

@@ -215,7 +215,7 @@ tls_max_connections=2048
 #!endif
 
 /* set it to yes to enable sctp and load sctp.so module */
-disable_sctp=yes
+enable_sctp=no
 
 ####### Custom Parameters #########