pkg: remove Makefile.defs.diff file, which set special daemon name - use the default

pkg/ser/gentoo/files/Makefile.defs.diff

@@ -1,11 +0,0 @@
---- Makefile.defs~	2011-03-22 14:57:24.759454311 -0300
-+++ Makefile.defs	2011-03-23 10:06:57.997000132 -0300
-@@ -133,7 +133,7 @@
- 
- ifeq ($(FLAVOUR),sip-router)
- # main binary name
--MAIN_NAME=ser
-+MAIN_NAME=siprouter
- else ifeq ($(FLAVOUR),ser)
- # main binary name
- MAIN_NAME=ser