Fix test failure when pkg.m4 is not found, only pkg-config. * tests/vala5.test: Update comment, this test is not expected to fail any more. Require valac version 0.7.0. Skip if configure fails, could be due to unexpanded PKG_CHECK_MODULES or too old valac. Report by Simon Josefsson. Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>