libvterm: Update to latest git master

packages/libvterm/build.sh

@@ -1,9 +1,11 @@
 TERMUX_PKG_HOMEPAGE=http://libvterm.sourceforge.net/
 TERMUX_PKG_DESCRIPTION="Terminal emulator library"
 # libvterm does not do releases, take a specific commit for now:
-TERMUX_PKG_VERSION=0.0.201601301200
-TERMUX_PKG_SRCURL=https://github.com/neovim/libvterm/archive/a9c7c6fd20fa35e0ad3e0e98901ca12dfca9c25c.zip
-TERMUX_PKG_FOLDERNAME=libvterm-a9c7c6fd20fa35e0ad3e0e98901ca12dfca9c25c
+TERMUX_PKG_VERSION=16.12.18
+_COMMIT=224b8dcde1c9640c29a34aa60c0f0d56ad298449
+TERMUX_PKG_SRCURL=https://github.com/neovim/libvterm/archive/$_COMMIT.zip
+TERMUX_PKG_SHA256=8b8ce8c26bc63e8b7934581d3ea5a3deaa3571009d4eaa777444f333951eeac5
+TERMUX_PKG_FOLDERNAME=libvterm-$_COMMIT
 TERMUX_PKG_BUILD_IN_SRC=yes
 
 termux_step_make () {