pkg02_b requires network

testsuite/tests/ghc-regress/cabal/pkg02/all.T

 # We can compile Network on its own (pkg02_a)
 
 test('pkg02_a', only_ways(['normal']), multimod_compile, ['Network','-v0'])
-test('pkg02_b', normal, multimod_compile, ['A','-v0'])
+test('pkg02_b', reqlib('network'), multimod_compile, ['A','-v0'])
 clean_o_hi()