python, python2: disable setuid in servers (#6548)

packages/python2/build.sh

@@ -4,7 +4,7 @@ TERMUX_PKG_LICENSE="PythonPL"
 TERMUX_PKG_MAINTAINER="@termux"
 _MAJOR_VERSION=2.7
 TERMUX_PKG_VERSION=${_MAJOR_VERSION}.18
-TERMUX_PKG_REVISION=4
+TERMUX_PKG_REVISION=5
 TERMUX_PKG_SRCURL=https://www.python.org/ftp/python/${TERMUX_PKG_VERSION}/Python-${TERMUX_PKG_VERSION}.tar.xz
 TERMUX_PKG_SHA256=b62c0e7937551d0cc02b8fd5cb0f544f9405bafc9a54d3808ed4594812edef43
 TERMUX_PKG_DEPENDS="libandroid-support, ncurses, readline, libffi, openssl, libbz2, libsqlite, gdbm, ncurses-ui-libs, libcrypt, zlib"

packages/python2/no-setuid-servers.patch

@@ -0,0 +1,36 @@
+diff -uNr Python-2.7.18/Lib/CGIHTTPServer.py Python-2.7.18.mod/Lib/CGIHTTPServer.py
+--- Python-2.7.18/Lib/CGIHTTPServer.py	2020-04-20 00:13:39.000000000 +0300
++++ Python-2.7.18.mod/Lib/CGIHTTPServer.py	2021-03-20 16:17:50.802196841 +0200
+@@ -239,10 +239,6 @@
+                 return
+             # Child
+             try:
+-                try:
+-                    os.setuid(nobody)
+-                except os.error:
+-                    pass
+                 os.dup2(self.rfile.fileno(), 0)
+                 os.dup2(self.wfile.fileno(), 1)
+                 os.execve(scriptfile, args, env)
+diff -uNr Python-2.7.18/Lib/smtpd.py Python-2.7.18.mod/Lib/smtpd.py
+--- Python-2.7.18/Lib/smtpd.py	2020-04-20 00:13:39.000000000 +0300
++++ Python-2.7.18.mod/Lib/smtpd.py	2021-03-20 16:17:42.182179072 +0200
+@@ -9,7 +9,8 @@
+     -n
+         This program generally tries to setuid `nobody', unless this flag is
+         set.  The setuid call will fail if this program is not run as root (in
+-        which case, use this flag).
++        which case, use this flag). Ignored in Termux as no setuid done on this
++        platform.
+ 
+     --version
+     -V
+@@ -461,7 +462,7 @@
+ 
+ 
+ class Options:
+-    setuid = 1
++    setuid = 0
+     classname = 'PureProxy'
+ 
+