tools/libressl: update to version 3.4.3

Release notes:
https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-3.4.3-relnotes.txt

```
It includes the following security fix:

    * A malicious certificate can cause an infinite loop.
      Reported by and fix from Tavis Ormandy and David Benjamin, Google.
```

Signed-off-by: Josef Schlehofer <[email protected]>

tools/libressl/Makefile

@@ -8,8 +8,8 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libressl
-PKG_VERSION:=3.4.2
-PKG_HASH:=cb82ca7d547336917352fbd23db2fc483c6c44d35157b32780214ec74197b3ce
+PKG_VERSION:=3.4.3
+PKG_HASH:=ff88bffe354818b3ccf545e3cafe454c5031c7a77217074f533271d63c37f08d
 PKG_RELEASE:=1
 
 PKG_CPE_ID:=cpe:/a:openbsd:libressl