ISO C99 and later do not support implicit int

[bcb]

When building, I had 3 errors like this:

#14 2.341 src/pg_amqp.c:140:21: error: parameter 'broker_id' was not declared, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
#14 2.341 local_amqp_get_a_bs(broker_id) {
#14 2.341                     ^

Changing the broker_id parameters to int broker_id allowed me to build.

[bcb]

Duplicate of #41