newsboat: use hardcoded length of mbc buffer

Issue https://github.com/termux/termux-packages/issues/7498

Android's MB_LEN_MAX is too small (4). On Linux distributions it is
usually 16, so using this value which resolved the older issue:
https://github.com/termux/termux-packages/issues/4334

packages/newsboat/build.sh

@@ -3,6 +3,7 @@ TERMUX_PKG_DESCRIPTION="RSS/Atom feed reader for the text console"
 TERMUX_PKG_LICENSE="MIT"
 TERMUX_PKG_MAINTAINER="@termux"
 TERMUX_PKG_VERSION=2.24
+TERMUX_PKG_REVISION=1
 TERMUX_PKG_SRCURL=https://newsboat.org/releases/${TERMUX_PKG_VERSION}/newsboat-${TERMUX_PKG_VERSION}.tar.xz
 TERMUX_PKG_SHA256=62420688cca25618859548d10ff6df9ac75b9cf766699f37edd3e324d67c6ffb
 TERMUX_PKG_DEPENDS="libc++, libiconv, libandroid-support, libandroid-glob, json-c, libsqlite, libcurl, libxml2, stfl, ncurses, openssl"

packages/newsboat/mbc-buffer-length-fix.patch

@@ -0,0 +1,21 @@
+diff -uNr newsboat-2.24/src/tagsouppullparser.cpp newsboat-2.24.mod/src/tagsouppullparser.cpp
+--- newsboat-2.24/src/tagsouppullparser.cpp	2021-06-20 20:40:09.000000000 +0300
++++ newsboat-2.24.mod/src/tagsouppullparser.cpp	2021-09-08 23:50:47.207115677 +0300
+@@ -445,7 +445,7 @@
+ 	if (s.length() > 1 && s[0] == '#') {
+ 		std::string result;
+ 		unsigned int wc;
+-		char mbc[MB_LEN_MAX];
++		char mbc[16];
+ 		mbc[0] = '\0';
+ 		if (s[1] == 'x') {
+ 			s.erase(0, 2);
+@@ -499,7 +499,7 @@
+ 	} else {
+ 		for (unsigned int i = 0; entity_table[i].entity; ++i) {
+ 			if (s == entity_table[i].entity) {
+-				char mbc[MB_LEN_MAX];
++				char mbc[16];
+ 				const int pos = wcrtomb(mbc, entity_table[i].value, &mb_state);
+ 				if (pos == -1) {
+ 					return std::string();