expected_error:0 fix a memory leak error reported by email in version <= 5.1.0
SIP/2.0 200 00
pro:0000000"luri="000 000
Authentication-info:00000000Ç000+0icate:ct: <sip:00000@000000000000:0000;transport=UDP>
Content-Type: a00li000i0n/000
Call-Info:0<00t00000000>;00000000000=0;0000=0000000l000;000=00000;0000=0;000000a0i00t0=0;0ri00000=00;0000000te0:00000000000000
a=0tp000:00000000000000
a=f00p:0040p00000000000;000000000000
a=0000:000 00o00000000000000000000;0ac0000000000o00=0
U000000000: 00C/00000
Content-Length:   394

v=0
I00 0000&0000000
s=
00 S0i
o=02000 0 0 00 I00 0000&0000000
s=
00 S0i000
c=0N IP4Content-Length:t=1 0
m=a000o 200020>;000=3000000000
To: <sip:00000@000020004000:000240040040
CSeq:020 I00000
Contact: <sip:00000@0000€0000000:0000000
a=0tp000:00000000000000
a=f00p:0040p00000000000;000000000000
a=0000:000 00o00000000000000000000;0ac00000000000m00e00000000000000000000l0o00000
a=r000