package/libcurl: fix build with mbedtls when h2-enabled

Bug was introduced by bumping libcurl to 7.83.0 in
https://git.busybox.net/buildroot/commit/?id=b0b25f145469a14e3d85becf19aaca0a40fd4e25

Fixes:
http://autobuild.buildroot.net/results/825/825b0ae84d5212200710628689079ec54a4bda3f/
http://autobuild.buildroot.net/results/881/8812ffdf42a3adf2df834c4b6e36316cd932821e/
http://autobuild.buildroot.net/results/3e8/3e840c896e4b8aacc9d784f16a6388eac4178246/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/libcurl/0001-mbedtls-fix-compile-when-h2-enabled.patch

@@ -0,0 +1,32 @@
+From 6eb7fb37d901ed1e4ce07cbd628ee11bf02db1f3 Mon Sep 17 00:00:00 2001
+From: Daniel Stenberg <daniel@haxx.se>
+Date: Thu, 28 Apr 2022 17:11:50 +0200
+Subject: [PATCH] mbedtls: fix compile when h2-enabled
+
+Fixes #8766
+Reported-by: LigH-de on github
+Closes #8768
+
+Downloaded from upstream commit
+https://github.com/curl/curl/commit/6eb7fb37d901ed1e4ce07cbd628ee11bf02db1f3
+
+Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
+---
+ lib/vtls/mbedtls.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c
+index 64f57c5d8321..5f9b87e6b75b 100644
+--- a/lib/vtls/mbedtls.c
++++ b/lib/vtls/mbedtls.c
+@@ -815,8 +815,8 @@ mbed_connect_step2(struct Curl_easy *data, struct connectdata *conn,
+     if(next_protocol) {
+       infof(data, VTLS_INFOF_ALPN_ACCEPTED_1STR, next_protocol);
+ #ifdef USE_HTTP2
+-      if(!strncmp(next_protocol, ALPN_H2, ALPN_H2_LEN) &&
+-         !next_protocol[ALPN_H2_LEN]) {
++      if(!strncmp(next_protocol, ALPN_H2, ALPN_H2_LENGTH) &&
++         !next_protocol[ALPN_H2_LENGTH]) {
+         conn->negnpn = CURL_HTTP_VERSION_2;
+       }
+       else