Remove unused variable

Author: AmedeeBulle

src/TheThingsNetwork.cpp

@@ -420,10 +420,10 @@ void TheThingsNetwork::autoBaud()
 void TheThingsNetwork::reset(bool adr)
 {
   autoBaud();
-  size_t length __attribute__((unused)) = readResponse(SYS_TABLE, SYS_RESET, buffer, sizeof(buffer));
+  readResponse(SYS_TABLE, SYS_RESET, buffer, sizeof(buffer));
 
   autoBaud();
-  length = readResponse(SYS_TABLE, SYS_TABLE, SYS_GET_VER, buffer, sizeof(buffer));
+  readResponse(SYS_TABLE, SYS_TABLE, SYS_GET_VER, buffer, sizeof(buffer));
 
   // buffer contains "RN2xx3[xx] x.x.x ...", splitting model from version
   char *model = strtok(buffer, " ");