sipsess coverity warning

[sreimers]

** CID 274764:  Null pointer dereferences  (REVERSE_INULL)
/src/sipsess/connect.c: 91 in invite_resp_handler()


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*** CID 274764:  Null pointer dereferences  (REVERSE_INULL)
/src/sipsess/connect.c: 91 in invite_resp_handler()
85     	if (msg->scode < 200) {
86     		sess->progrh(msg, sess->arg);
87     
88     		if (sip_msg_hdr_has_value(msg, SIP_HDR_REQUIRE, "100rel")
89     				&& sess->rel100_supported) {
90     
>>>     CID 274764:  Null pointer dereferences  (REVERSE_INULL)
>>>     Null-checking "msg" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
91     			if (msg && mbuf_get_left(msg->mb)) {
92     				if (sess->sent_offer) {
93     					sess->awaiting_answer = false;
94     					err = sess->answerh(msg, sess->arg);
95     					if (err)
96     						goto out;

** CID 274763:  Control flow issues  (DEADCODE)
/src/sipsess/accept.c: 113 in sipsess_accept()


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*** CID 274763:  Control flow issues  (DEADCODE)
/src/sipsess/accept.c: 113 in sipsess_accept()
107     	}
108     	else if (scode >= 200) {
109     		err = sipsess_reply_2xx(sess, msg, scode, reason, desc,
110     					fmt, &ap);
111     	}
112     	else {
>>>     CID 274763:  Control flow issues  (DEADCODE)
>>>     Execution cannot reach this statement: "struct sip_contact contact;".
113     		struct sip_contact contact;
114     
115     		sip_contact_set(&contact, sess->cuser, &msg->dst, msg->tp);
116     
117     		err = sip_treplyf(&sess->st, NULL, sess->sip,
118     				  msg, true, scode, reason,

@cspiel1 @maximilianfridrich can you check this?