mtr: add patch to remove setuid call

Reported in https://github.com/termux/termux-root-packages/issues/247

root-packages/mtr/build.sh

@@ -3,7 +3,7 @@ TERMUX_PKG_DESCRIPTION="Network diagnostic tool"
 TERMUX_PKG_LICENSE="GPL-2.0"
 TERMUX_PKG_MAINTAINER="@termux"
 TERMUX_PKG_VERSION=0.94
-TERMUX_PKG_REVISION=1
+TERMUX_PKG_REVISION=2
 TERMUX_PKG_SRCURL=https://github.com/traviscross/mtr/archive/v${TERMUX_PKG_VERSION}.tar.gz
 TERMUX_PKG_SHA256=ea036fdd45da488c241603f6ea59a06bbcfe6c26177ebd34fff54336a44494b8
 TERMUX_PKG_DEPENDS="ncurses"

root-packages/mtr/packet.c.patch

@@ -0,0 +1,18 @@
+--- ./packet/packet.c.orig	2021-09-10 21:20:26.554615393 +0200
++++ ./packet/packet.c	2021-09-10 21:22:52.034900909 +0200
+@@ -44,15 +44,6 @@
+     cap_t cap;
+ #endif
+ 
+-    /*  Drop any suid permissions granted  */
+-    if (setgid(getgid()) || setuid(getuid())) {
+-        return -1;
+-    }
+-
+-    if (geteuid() != getuid() || getegid() != getgid()) {
+-        return -1;
+-    }
+-
+     /*
+        Drop all process capabilities.
+        This will revoke anything granted by a commandline 'setcap'