revert back to usign autogen.sh cmdline arguments if given

This is a partial revert of ca0c54d0 .
Ignoring cmdline arguments if autogen.* exists is broken for several reasons:
- autogen.sh of every other package passes cmdline arguments to configure
- that's because if I was bothered to give them, I want them used
- there's no reason to prefer autogen.input now, given that autogen.input
  cannot be overwritten by autogen.sh, unlike autogen.lastrun , so there's
  no accidental loss of the switches
- running autogen.sh --foo followed by autogen.sh --bar actually runs
  configure with --foo the second time too, because the first one creates
  autogen.lastrun and the second one first complains about the cmdline
  args, then complains about autogen.lastrun, and then uses it

Change-Id: I5868610935d0312915be74602b6435eea069f937
Reviewed-on: https://gerrit.libreoffice.org/3190Reviewed-by: Luboš Luňák <l.lunak@suse.cz>
Tested-by: Luboš Luňák <l.lunak@suse.cz>

autogen.sh

@@ -112,14 +112,14 @@ my @cmdline_args = ();
 my $input = "autogen.input";
 my $lastrun = "autogen.lastrun";
 
-if (-f $input) {
-    warn "Ignoring command-line arguments, using $input.\n" if (@ARGV);
-    warn "Ignoring $lastrun, using $input.\n" if (-f $lastrun);
-    @cmdline_args = read_args ($input);
-} elsif (-f $lastrun) {
-    warn "Ignoring command-line arguments, using $lastrun.\n" if (@ARGV);
-    print STDERR "Reading $lastrun. Please rename it to $input to avoid this message.\n";
-    @cmdline_args = read_args ($lastrun);
+if (!@ARGV) {
+    if (-f $input) {
+        warn "Ignoring $lastrun, using $input.\n" if (-f $lastrun);
+        @cmdline_args = read_args ($input);
+    } elsif (-f $lastrun) {
+        print STDERR "Reading $lastrun. Please rename it to $input to avoid this message.\n";
+        @cmdline_args = read_args ($lastrun);
+    }
 } else {
     @cmdline_args = @ARGV;
 }