[chronojump] Fixes a problem when executing initltool-merge -m in po/ directory.

[Carles Pina i Estany <carlespina src gnome org>]

commit b4d33d9ee56d97aa39cd67355dacdfdaa7bf7d0a
Author: Carles Pina i Estany <carles pina cat>
Date:   Fri Nov 18 12:41:04 2016 +0100

    Fixes a problem when executing initltool-merge -m in po/ directory.
    
    Since 94d16f332e44e5f83e6a2fbbc2dcc446d6fedd29 when I replaced:
    AC_INIT([chronojump], [1.6.2])
    
    with:
    AC_INIT([chronojump], [m4_esyscmd_s([git describe --abbrev=0])])
    
    and because initltool-merge doesn't handle m4_esyscmd_s,when executing
    inittool-merge -m in po/ the output was:
    ----
    Unmatched ( in regex; marked by <-- HERE in m/^chronojump-m4_esyscmd_s(
    <-- HERE echo-n`gitdescribe`/.*$/ at /usr/bin/intltool-update line 320,
    <FILE> line 119.
    ----
    
    In this commit it avoids using m4_esyscmd_s. A bug with a patch for
    intltool-merge has been sent as well:
    https://bugs.launchpad.net/intltool/+bug/1642931

 configure.ac |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 1a93fda..03644b4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,10 @@ AC_PREREQ([2.54])
 
 # PACKAGE_VERSION variable comes from here (e.g. to show it to the user,
 # distribution package names, etc.)
-AC_INIT([chronojump], [m4_esyscmd_s([git describe])])
+
+# We are not using m4_esyscmd_s (then we wouldn't need the echo -n ``) because
+# of a bug in intltool-update. See: https://bugs.launchpad.net/intltool/+bug/1642931
+AC_INIT([chronojump], [m4_esyscmd([echo -n `git describe`])])
 
 # This is used in AssemblyInfo.cs.in: it can only be major.minor.release format
 AC_SUBST([PACKAGE_SIMPLIFIED_VERSION], [m4_esyscmd_s([git describe --abbrev=0])])