libnetwork.lib: git.create_tarball(): only clone the last commit

Signed-off-by: Davide Madrisan <davide.madrisan@gmail.com>

ChangeLog

@@ -4,6 +4,12 @@ Changes in version 1.12.5
   * autospec.spec - Davide Madrisan:
     Add a build requirement for gettext.
 
++ improvement
+  * lib/libnetwork.lib - Davide Madrisan:
+    git.create_tarball(): run 'git clone --depth=1' to only clone the last
+    commit. We do not need to clone the whole git repository.
+    (Thanks to Silvan Calarco:silvan.calarco(a)mambasoft.it for spotting this.)
+
 -------------------------------------------------------------------------------
 
 Changes in version 1.12.4

lib/libnetwork.lib.in

@@ -924,7 +924,7 @@ function git.create_tarball() {
    notify.note \
       "${NOTE}"$"cloning git repository""\
  <$git_repository> ${git_branch:+($git_branch)}${NORM}""..."
-   git clone ${git_branch:+-b $git_branch} "$git_repository"
+   git clone --depth=1 ${git_branch:+-b $git_branch} "$git_repository"
    [ $? -eq 0 ] ||
     { popd &>/dev/null
       rm -fr $tmpgitdir