busybox: remove useless busybox patches

The first two are useless as /bin/sh can execute those scripts just
fine. Shellcheck reports no problems.

Telnetd patch is useless as telnet is no longer used in OpenWrt.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

package/utils/busybox/patches/100-trylink_bash.patch

@@ -1,8 +0,0 @@
---- a/scripts/trylink
-+++ b/scripts/trylink
-@@ -1,4 +1,4 @@
--#!/bin/sh
-+#!/usr/bin/env bash
- 
- debug=false
- 

package/utils/busybox/patches/101-gen_build_files_bash.patch

@@ -1,8 +0,0 @@
---- a/scripts/gen_build_files.sh
-+++ b/scripts/gen_build_files.sh
-@@ -1,4 +1,4 @@
--#!/bin/sh
-+#!/usr/bin/env bash
- 
- # Note: was using sed OPTS CMD -- FILES
- # but users complain that many sed implementations

package/utils/busybox/patches/240-telnetd_intr.patch

@@ -1,10 +0,0 @@
---- a/networking/telnetd.c
-+++ b/networking/telnetd.c
-@@ -509,6 +509,7 @@ make_new_session(
- 
- 	/* Restore default signal handling ASAP */
- 	bb_signals((1 << SIGCHLD) + (1 << SIGPIPE), SIG_DFL);
-+	signal(SIGINT, SIG_DFL);
- 
- 	pid = getpid();
-