Remove compiler warnings in defaults.c

This patch removes these warnings:

defaults.c: In function ‘getFont’:
defaults.c:2011:84: warning: unused parameter ‘addr’ [-Wunused-parameter]
 static int getFont(WScreen * scr, WDefaultEntry * entry, WMPropList * value, void *addr, void **ret)
                                                                                    ^
defaults.c: In function ‘getColor’:
defaults.c:2036:85: warning: unused parameter ‘addr’ [-Wunused-parameter]
 static int getColor(WScreen * scr, WDefaultEntry * entry, WMPropList * value, void *addr, void **ret)