bug#11323: automake-1.11.4 regression

[Ralf Corsepius]

Hi,

With automake < 1.11.4 it was possible to create empty directories this way:
Makefile.am:
mystatedir = $(pkglocalstatedir)
mystatedir_DATA =


With automake-1.11.4, this doesn't work anymore and silently breaks 
existing Makefile.ams.

Ralf