configure: output vserver as implied if ancient-vserver is enabled

The build time configuration ancient-vserver implies the configuration
vserver; say so in the configure status report if only ancient-vserver
has been specified.

Also indent with 3 spaces.
diff --git a/configure.ac b/configure.ac
index 32e89cf..f056f41 100644
--- a/configure.ac
+++ b/configure.ac
@@ -472,7 +472,7 @@
               [],
               [enable_vserver=no])
 if test "x$enable_vserver" = xyes; then
-    AC_DEFINE([HAVE_VSERVER], [1], [Define if VServer support enabled.])
+   AC_DEFINE([HAVE_VSERVER], [1], [Define if VServer support enabled.])
 fi
 
 
@@ -482,8 +482,11 @@
               [],
               [enable_ancient_vserver=no])
 if test "x$enable_ancient_vserver" = xyes; then
-    AC_DEFINE([HAVE_VSERVER], [1], [Define if VServer support enabled.])
-    AC_DEFINE([HAVE_ANCIENT_VSERVER], [1], [Define if ancient vserver support enabled.])
+   if test "x$enable_vserver" != xyes; then
+      enable_vserver=implied
+   fi
+   AC_DEFINE([HAVE_VSERVER], [1], [Define if VServer support enabled.])
+   AC_DEFINE([HAVE_ANCIENT_VSERVER], [1], [Define if ancient vserver support enabled.])
 fi