ruby: More /system/bin/sh -> $PREFIX/bin/sh

packages/ruby/mkmf.rb.patch

@@ -6,7 +6,7 @@ diff -u -r ../ruby-2.1.2/lib/mkmf.rb ./lib/mkmf.rb
      CONFIG["hdrdir"] ||= $hdrdir
      mk << %{
 -SHELL = /bin/sh
-+SHELL = /system/bin/sh
++SHELL = @TERMUX_PREFIX@/bin/sh
  
  # V=0 quiet, V=1 verbose.  other values don't work.
  V = 0