Update runtime files.

runtime/filetype.vim

@@ -1,7 +1,7 @@
 " Vim support file to detect file types
 "
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
-" Last Change:	2018 Jan 28
+" Last Change:	2018 May 04
 
 " Listen very carefully, I will say this only once
 if exists("did_load_filetypes")
@@ -429,6 +429,13 @@ au BufNewFile,BufRead control
 	\|   setf debcontrol
 	\| endif
 
+" Debian Copyright
+au BufNewFile,BufRead */debian/copyright	setf debcopyright
+au BufNewFile,BufRead copyright
+	\  if getline(1) =~ '^Format:'
+	\|   setf debcopyright
+	\| endif
+
 " Debian Sources.list
 au BufNewFile,BufRead */etc/apt/sources.list		setf debsources
 au BufNewFile,BufRead */etc/apt/sources.list.d/*.list	setf debsources