Patch for busybox to accept + in emails (#760)

Since the termux mailinglist has a + in the subscibe mail address, this
is required.

packages/busybox/build.sh

@@ -2,7 +2,7 @@ TERMUX_PKG_HOMEPAGE=https://busybox.net/
 TERMUX_PKG_DESCRIPTION="Tiny versions of many common UNIX utilities into a single small executable"
 TERMUX_PKG_ESSENTIAL=yes
 TERMUX_PKG_VERSION=1.26.2
-TERMUX_PKG_REVISION=2
+TERMUX_PKG_REVISION=3
 TERMUX_PKG_SRCURL=https://busybox.net/downloads/busybox-${TERMUX_PKG_VERSION}.tar.bz2
 TERMUX_PKG_SHA256=da3e44913fc1a9c9b7c5337ea5292da518683cbff32be630777f565d6036af16
 TERMUX_PKG_BUILD_IN_SRC=yes

packages/busybox/sendmail.patch

@@ -0,0 +1,13 @@
+diff --git a/mailutils/sendmail.c b/mailutils/sendmail.c
+index 8ddb782..b542099 100644
+--- a/mailutils/sendmail.c
++++ b/mailutils/sendmail.c
+@@ -150,7 +150,7 @@ static char *sane_address(char *str)
+ 	trim(str);
+ 	s = str;
+ 	while (*s) {
+-		if (!isalnum(*s) && !strchr("_-.@", *s)) {
++		if (!isalnum(*s) && !strchr("+_-.@", *s)) {
+ 			bb_error_msg("bad address '%s'", str);
+ 			/* returning "": */
+ 			str[0] = '\0';