aqhome: fixed mqtt message handling

PUBLISH: the message itself is NOT preceeded by size

aqhome/mqtt/endpoint_mqttc.c

@@ -474,6 +474,7 @@ int _calcAndSetPayloadSizeAndOffset(GWEN_MSG *msg)
   if (remainingBytesInBuffer>1) {
     const uint8_t *ptr;
     int idx;
+    int shift=0;
 
     ptr=GWEN_Msg_GetConstBuffer(msg);
     idx=1;
@@ -482,8 +483,7 @@ int _calcAndSetPayloadSizeAndOffset(GWEN_MSG *msg)
       uint8_t len;
 
       len=ptr[idx];
-      mqttRemainingLength<<=8;
-      mqttRemainingLength+=(len & 0x7f);
+      mqttRemainingLength+=(len & 0x7f)<<shift;
       if (!(len & 0x80)) {
         /* last byte of size */
         GWEN_Msg_SetParsedPayloadSize(msg, mqttRemainingLength);
@@ -491,6 +491,9 @@ int _calcAndSetPayloadSizeAndOffset(GWEN_MSG *msg)
         GWEN_Msg_AddFlags(msg, GWEN_MSG_FLAGS_PAYLOADINFO_SET);
         return 1; /* size successfully determined */
       }
+      shift+=7;
+      idx++;
+      remainingBytesInBuffer--;
     }
   }
   return 0;