[gnc-prefs.cpp] convert to c++

Author: christopherlam

libgnucash/core-utils/CMakeLists.txt

@@ -6,7 +6,7 @@ add_subdirectory(test)
 ### libgnc-core-utils
 set (core_utils_SOURCES
   binreloc.c
-  gnc-prefs.c
+  gnc-prefs.cpp
   gnc-environment.c
   gnc-filepath-utils.cpp
   gnc-gkeyfile-utils.c

libgnucash/core-utils/gnc-prefs.c renamed to libgnucash/core-utils/gnc-prefs.cpp

@@ -619,7 +619,7 @@ libgnucash/core-utils/gnc-glib-utils.c
 libgnucash/core-utils/gnc-locale-utils.c
 libgnucash/core-utils/gnc-locale-utils.cpp
 libgnucash/core-utils/gnc-path.c
-libgnucash/core-utils/gnc-prefs.c
+libgnucash/core-utils/gnc-prefs.cpp
 libgnucash/core-utils/gnc-unicode.cpp
 libgnucash/core-utils/gnc-version.c
 libgnucash/engine/Account.cpp