Don't use + (plus) in automake variable names.

Use _ (underscore) instead.

This fixes regression where the include files were not installed
anymore. This happened on rename of libdns to libdns++.

(Ooops I should have caught this earlier ... since my release
engineering checklist had item to test building software using
libraries.)


git-svn-id: svn://bind10.isc.org/svn/bind10/trunk@2975 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/dns/Makefile.am

@@ -88,8 +88,8 @@ rrparamregistry.cc: rrparamregistry-placeholder.cc
 rrclass.h rrtype.h rrparamregistry.cc rdataclass.h rdataclass.cc: Makefile
 	./gen-rdatacode.py
 
-libdns++_includedir = $(includedir)/dns
-libdns++_include_HEADERS = \
+libdns___includedir = $(includedir)/dns
+libdns___include_HEADERS = \
 	buffer.h \
 	dnssectime.h \
 	exceptions.h \