multimedia/icecast: fix PKG_CPE_ID

cpe:/a:xiph:icecast is the correct CPE ID for icecast:
https://nvd.nist.gov/products/cpe/search/results?keyword=cpe:2.3:a:xiph:icecast

Fixes: a36f265 (icecast: Update to 2.4.4)

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>

Author: ffontaine

multimedia/icecast/Makefile

@@ -18,7 +18,7 @@ PKG_MAINTAINER:=André Gaul <andre@gaul.io>, \
 
 PKG_LICENSE:=GPL-2.0
 PKG_LICENSE_FILES:=COPYING
-PKG_CPE_ID:=cpe:/a:icecast:icecast
+PKG_CPE_ID:=cpe:/a:xiph:icecast
 
 PKG_FIXUP:=autoreconf
 PKG_INSTALL:= 1