ruby: Drop patch no longer needed

packages/ruby/src-signal.c.patch

@@ -1,14 +0,0 @@
-REG_RSP is an enum value in the NDK so cannot be ifdef checked.
-
-diff -u -r ../ruby-2.3.1/signal.c ./signal.c
---- ../ruby-2.3.1/signal.c	2015-11-23 19:17:11.000000000 -0500
-+++ ./signal.c	2016-06-17 17:15:18.947494468 -0400
-@@ -771,7 +771,7 @@
- {
-     const DEFINE_MCONTEXT_PTR(mctx, ctx);
- # if defined __linux__
--#   if defined REG_RSP
-+#   if defined __x86_64__
-     const greg_t sp = mctx->gregs[REG_RSP];
- #   else
-     const greg_t sp = mctx->gregs[REG_ESP];