bigtable: small emulator validation fix
bigtable: small emulator validation fix

Fixes #1120

Change-Id: I37e61ddd50766aede323d7b9690635efcb5a5074
Reviewed-on: https://code-review.googlesource.com/32170
Reviewed-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Solomon Duskis <389fd494afe31cb024cec281057417f4d81cbc59@google.com>
Reviewed-by: Jean de Klerk <605b93664484fed1e671a07bff68da39e73d0174@google.com>
Reviewed-by: Jonathan Amsterdam <e3d3698b2ccd5955e4adf250d0785062d0f9018b@google.com>

googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go