Fix bug in GTK+3 logic introduced by previous merge

During merging of conflicting versions of this file, I erroneously
deleted several lines in the GUI reporting section. This is repaired
in this commit.

CMakeLists.txt

@@ -749,7 +749,15 @@ else()
         status("    Cocoa:"  YES)
       endif()
     else()
+      if(HAVE_GTK3)
+        status("    GTK+ 3.x:" HAVE_GTK     THEN "YES (ver ${ALIASOF_gtk+-3.0_VERSION})"     ELSE NO)
+      elseif(HAVE_GTK)
         status("    GTK+ 2.x:" HAVE_GTK      THEN "YES (ver ${ALIASOF_gtk+-2.0_VERSION})"     ELSE NO)
+      else()
+        if(DEFINED WITH_GTK)
+          staus("    GTK+:" NO)
+        endif()
+      endif()
       status("    GThread :" HAVE_GTHREAD  THEN "YES (ver ${ALIASOF_gthread-2.0_VERSION})"  ELSE NO)
       status("    GtkGlExt:" HAVE_GTKGLEXT THEN "YES (ver ${ALIASOF_gtkglext-1.0_VERSION})" ELSE NO)
     endif()