http interface / SMSC sets various parameters to 0 instead of undef

        Hi,

 While investigating how to override the resulting data coding of
 outgoing SMPP submit_reqs, I noticed that the HTTP interface to send
 SM sets:
    mclass = mwi = coding = validity = deferred = 0;
 (gw/smsc/smsc_http.c:415)

 effectively deactivating all other logic in Kannel which might set the
 these parameters based on interesting properties.  For example, if
 coding is unset, Kannel will check whether the udh is defined and
 non-empty and then set coding to 1 or 0.  The same goes for mclass or
 the resulting data coding.

 It seems to me this should be:
    mclass = mwi = coding = validity = deferred = MSG_PARAM_UNDEFINED;
    (or SMS_PARAM_UNDEFINED)

   Bye,
-- 
Loïc Minier <[email protected]>