[glibmm] Doxyfile.in: Remove unused configuration constants

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 0e8e956d1c5e88597c06ecae4dcc5d2f98ce86ed
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Thu Mar 21 15:56:35 2019 +0100

    Doxyfile.in: Remove unused configuration constants
    
    Should have been done when they were removed from other files in
    the fix of issue #22.

 docs/reference/Doxyfile.in | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
---
diff --git a/docs/reference/Doxyfile.in b/docs/reference/Doxyfile.in
index 51dec039..5b4820c9 100644
--- a/docs/reference/Doxyfile.in
+++ b/docs/reference/Doxyfile.in
@@ -303,11 +303,7 @@ PREDEFINED             = __cplusplus \
                          G_OS_WIN32 \
                          "GLIBMM_API=" \
                          "GIOMM_API=" \
-                         GLIBMM_DEFAULT_SIGNAL_HANDLERS_ENABLED \
-                         GLIBMM_EXCEPTIONS_ENABLED \
-                         GLIBMM_HAVE_WIDE_STREAM \
-                         GLIBMM_PROPERTIES_ENABLED \
-                         GLIBMM_VFUNCS_ENABLED
+                         GLIBMM_HAVE_WIDE_STREAM
 EXPAND_AS_DEFINED      = GLIBMM_MAJOR_VERSION \
                          GLIBMM_MINOR_VERSION \
                          GLIBMM_MICRO_VERSION \