Fix typo in build_wrapper.py

Change-Id: Ie61b1f3cfd2bc2bf8a19bb4c2716ac03a70ffa11
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>
build_wrapper: Add missing ':' for an 'if' statement

Change-Id: I074c1b9ac32eba3a19ab63f5fb923ecb6040ad0e
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>