Makefile.in: added missing CXX variable.
diff --git a/Makefile.in b/Makefile.in
index 81c56fd..69f5cb1 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -19,6 +19,7 @@ distfile = $(distdir).tar.gz
@SET_MAKE@
SHELL = @SHELL@
CC = @CC@
+CXX = @CXX@
INCLUDE = @INCLUDE@
CFLAGS = @BUILD_CFLAGS@
EXTRA_CFLAGS = @EXTRA_CFLAGS@