remove obsolete config.mak example

config.mak is autogenerated by the configure script since a long time.
there's no need to supply the example anymore, and it appears a lot
of people are looking into the directory expecting to find a binary
distribution.

dist/config.mak

@@ -1,11 +0,0 @@
-### config.mak template for proxychains
-#######################################
-
-# just copy into proxychains root dir and adapt to your needs.
-
-prefix = /usr/local/
-libdir = $(prefix)/lib
-
-exec_prefix = /usr/local
-bindir = $(exec_prefix)/bin
-