rmvtransport: make filters always effective
In the `rmvtransport` integration, the three config attributes
`destination`, `lines`, and `time_offset` all act as filters. The
expectation is that if multiple filters are given, all of them take
effect.
However, as a consequence of using `elif` in the loop body, if a
`destination` filter has been configured, then both the `lines` and the
`time_offset` filters are ignored and have no effect.
Replace the `elif` with an `if` clause to allow all filter settings to
work as intended.
CC: @cgtobi
baa79303a7