move DMAIN definition to new debug.h

This way both client.h and bankd.h don't conflict with each other

Change-Id: I68ffd64e1f32b90206f98c7f3ea707d7b2e11e61
diff --git a/src/Makefile.am b/src/Makefile.am
index 12b1e7b..ca799ce 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -12,7 +12,7 @@
 			  rspro/libosmo-asn1-rspro.la
 libosmo_rspro_la_SOURCES = rspro_util.c
 
-noinst_HEADERS = bankd.h client.h internal.h rspro_util.h \
+noinst_HEADERS = debug.h bankd.h client.h internal.h rspro_util.h \
 		 simtrace2/apdu_dispatch.h \
 		 simtrace2/libusb_util.h \
 		 simtrace2/simtrace2-discovery.h \