Merge Monson Shao's 'check-gdk' into stable.

CMakeLists.txt

@@ -783,11 +783,13 @@ set_property(TARGET PkgConfig::GLIB2 PROPERTY INTERFACE_COMPILE_DEFINITIONS
   GLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_${GLIB_API}
   GLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_${GLIB_API})
 
+if (WITH_GNUCASH)
 string(REGEX MATCH "^([0-9]+)\.([0-9]+)" GTK_MIN_MATCH ${GTK_MIN_VERSION})
 set(GTK_API ${CMAKE_MATCH_1}_${CMAKE_MATCH_2})
 set_property(TARGET PkgConfig::GTK3 PROPERTY INTERFACE_COMPILE_DEFINITIONS
   GDK_VERSION_MIN_REQUIRED=GDK_VERSION_${GTK_API}
   GDK_VERSION_MAX_ALLOWED=GDK_VERSION_${GTK_API})
+endif()
 
 add_definitions (-DHAVE_CONFIG_H)