排查rtmp协议推流时握手bug

转推流程序的过程：从一个观看地址拉流，然后推流到另一个推流地址。主要用于cdn之间转推，目前市面上大多数cdn厂商都愿意不支持动态转推，因此只能通过转推流程序进行转推。

bug现象：使用obs studio推流到微赞可以成功，但是使用Erlang版本的转推流程序推流到微赞却失败。

日志如下：

14:12:35.926 [debug] payload [{amf,["onBWDone",0,null]}], msgtype[command_msg_4_amf0] 
14:12:35.949 [debug] play succ ======> url ["/live-sz/w1520993434573948"] 
14:12:35.949 [debug] {rtmp_msg,4,0,data_msg_4_amf0,1,{amf,["|RtmpSampleAccess",true,true]}}
14:12:35.949 [debug] {rtmp_msg,4,0,data_msg_4_amf0,1,{amf,["onStatus",{object,[{"code","NetStream.Data.Start"}]}]}}
14:12:36.038 [error] gen_server <0.122.0> terminated with reason: no match of right hand value <<0,0,0,0,0,0,0,0,113,142,194,240,185,25,41,180,242,33,5,112,128,97,178,8,79,179,28,53,152,242,82,43,234,104,113,246,170,189,182,146,122,36,155,3,152,180,226,122,36,97,52,67,53,158,107,170,178,119,209,132,40,233,102,182,142,233,218,71,55,8,121,67,117,58,130,91,107,224,202,5,1,132,37,245,143,231,20,198,121,204,57,80,102,165,104,245,79,71,254,169,15,3,166,12,148,45,24,62,253,66,93,139,84,139,54,236,47,5,98,95,51,231,222,144,8,153,232,166,227,151,57,98,214,63,238,167,212,49,51,160,83,248,246,199,...>> in rtmp_handshake:create_c2/2 line 61

很显然是rtmp_handshake:create_c2/2函数出现匹配错误，对应代码如下：

-spec create_c2(C0C1, S0S1S2) -> Result when
          C0C1 :: iodata(),
          S0S1S2 :: binary(),
          Result :: {ok, C2},
          C2 :: iolist().
create_c2(C0C1, S0S1S2) when is_list(C0C1) ->
    create_c2(iolist_to_binary(C0C1), S0S1S2);
create_c2(<<_C0:1/binary, C1:16#600/binary>>, <<<<<<<<<&uptime&clientsig<<&type&suptime<<<<<<<<<