vimpc: migrate to pkgconf

Author: cho-m

Formula/v/vimpc.rb

@@ -26,7 +26,7 @@ class Vimpc < Formula
   depends_on "autoconf" => :build
   depends_on "automake" => :build
   depends_on "libtool" => :build
-  depends_on "pkg-config" => :build
+  depends_on "pkgconf" => :build
 
   depends_on "libmpdclient"
   depends_on "pcre"