sylpheed: fix license files typo

As pointed out by Arnout.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/sylpheed/sylpheed.mk

@@ -9,7 +9,7 @@ SYLPHEED_VERSION = $(SYLPHEED_VERSION_MAJOR).$(SYLPHEED_VERSION_MINOR)
 SYLPHEED_SOURCE = sylpheed-$(SYLPHEED_VERSION).tar.bz2
 SYLPHEED_SITE = http://sylpheed.sraoss.jp/sylpheed/v$(SYLPHEED_VERSION_MAJOR)
 SYLPHEED_LICENSE = GPLv2+ (executables), LGPLv2.1+ (library, attachment plugin)
-SYLPHEED_LICENSE_FILES = COPIYNG COPYING.LIB
+SYLPHEED_LICENSE_FILES = COPYING COPYING.LIB
 
 SYLPHEED_CONF_OPT = --disable-gtkspell