[gnome-calculator] Use AM_DISTCHECK_CONFIGURE_FLAGS

[Michael Catanzaro <mcatanzaro src gnome org>]

commit e7a82529d5829ffb86e29e4a2e87cb31cd8a1774
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Tue Jan 12 12:05:35 2016 -0600

    Use AM_DISTCHECK_CONFIGURE_FLAGS
    
    The purpose of DISTCHECK_CONFIGURE_FLAGS is for the user to override
    AM_DISTCHECK_CONFIGURE_FLAGS. Overriding it breaks that.

 Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index babbeb6..2e9150f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,6 +1,6 @@
 SUBDIRS = data lib src search-provider tests help po
 
-DISTCHECK_CONFIGURE_FLAGS = --enable-installed-tests
+AM_DISTCHECK_CONFIGURE_FLAGS = --enable-installed-tests
 
 MAINTAINERCLEANFILES = \
        $(GITIGNORE_MAINTAINERCLEANFILES_TOPLEVEL) \