[gnome-weather] build: add AC_PROG_LN_S

[Dominique Leuenberger <dleuen src gnome org>]

commit 23440bd883fe9b2c8acca58b9c9157ef4cf355a1
Author: Dominique Leuenberger <dimstar opensuse org>
Date:   Wed Mar 4 09:02:45 2015 +0100

    build: add AC_PROG_LN_S
    
    After the refactoring of the build system, we lost the implicit
    declaration of $(LN_S), resulting in the symlink in $(bindir) no longer
    to be created.
    
    Instead, the build/install log contained:
      [   52s] /usr/bin/mkdir -p
      /home/abuild/rpmbuild/BUILDROOT/gnome-weather-3.15.91-0.x86_64/usr/bin
      [   52s] f /usr/share/org.gnome.Weather/org.gnome.Weather.Application
      /home/abuild/rpmbuild/BUILDROOT/gnome-weather-3.15.91-0.x86_64/usr/bin/gnome-weather
      [   52s] make[3]: f: Command not found
      [   52s] Makefile:563: recipe for target 'install-exec-hook' failed
      [   52s] make[3]: [install-exec-hook] Error 127 (ignored)
    
    https://bugzilla.gnome.org/show_bug.cgi?id=745581

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0abb0b6..714c8d2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,6 +15,7 @@ AM_SILENT_RULES([yes])
 GETTEXT_PACKAGE=$PACKAGE_NAME
 AC_SUBST(GETTEXT_PACKAGE)
 IT_PROG_INTLTOOL(0.26)
+AC_PROG_LN_S
 
 PKG_PROG_PKG_CONFIG([0.22])