Fix opq_osm_id for more than 1 id

[jmaspons]

Fix #268

Examples on the documentation now works

[mpadge]

Thanks @jmaspons, that is indeed what is needed to fix that. Before merging, could you please also update the corresponding tests?

osmdata/tests/testthat/test-opq.R

Lines 132 to 135 in 39d7994

	expect_error (
	opq_osm_id (type = "node", id = 1:2 + 0.1),
	"Only a single id may be entered."
	)

That no longer triggers an error, so you could just change expect_error to expect_s3_class, with an expected value of "overpass_query", like the example a couple of tests further. Once that's done, I'll be happy to merge. Thanks!