Fix missing dependency in 'src/hs2py-constants'

Fix target 'src/hs2py-constants' because it must depend on
'src/AutoConf.hs'. Fixes issue 573.
Signed-off-by: Jose A. Lopes <jabolopes@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Makefile.am

@@ -918,9 +918,9 @@ endif
 # because 'hs2py-constants' cannot depend on 'Ganeti.Constants'.  And
 # the reason for this is because 'hs2py-constants' needs to generate
 # Python code, and 'Ganeti.Constants' is generated by Python.
-src/hs2py-constants: src/hs2py-constants.hs src/Ganeti/BasicTypes.hs \
-		     src/Ganeti/JSON.hs src/Ganeti/THH.hs \
-		     src/Ganeti/Hs2Py/GenConstants.hs \
+src/hs2py-constants: src/hs2py-constants.hs src/AutoConf.hs \
+		     src/Ganeti/BasicTypes.hs src/Ganeti/JSON.hs \
+		     src/Ganeti/THH.hs src/Ganeti/Hs2Py/GenConstants.hs \
 		     src/Ganeti/Hs2Py/ListConstants.hs \
 		     src/Ganeti/HsConstants.hs \
 		     src/Ganeti/PyValueInstances.hs \