[master] make descend into testdata directory before local tests

I mentioned this on jabber last week:
Why would it want to do the local directory tests before the testdata
is generated?

This issue is never noticed yet because the testdata was built
at build time and not check time.

src/lib/datasrc/tests/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS = . testdata
+SUBDIRS = testdata
 
 AM_CPPFLAGS = -I$(top_srcdir)/src/lib -I$(top_builddir)/src/lib
 AM_CPPFLAGS += -I$(top_builddir)/src/lib/dns -I$(top_srcdir)/src/lib/dns