SCTP: avoid assert on partial SCTP message

The receive buffer for SCTP, as of this commit, is 8192. If a message is
larger, we receive only a partial message, which makes the gNB abort.
Remove the abort to not be susceptible to a message intended to crash
the gNB.

Closes: #920

openair3/SCTP/sctp_eNB_task.c

@@ -806,8 +806,8 @@ sctp_eNB_read_from_socket(
     }
 
     if (!(flags & MSG_EOR)) {
-      SCTP_ERROR("fatal: partial SCTP messages are not handled\n");
-      exit_fun("fatal: partial SCTP messages are not handled" );
+      SCTP_ERROR("partial SCTP message received, discarding message\n");
+      return;
     }
 
     if (flags & MSG_NOTIFICATION) {