update xgboost 1.4.2

Author: vaaaaanquish

.gitmodules

@@ -1,4 +1,4 @@
 [submodule "xgboost-sys/xgboost"]
 	path = xgboost-sys/xgboost
-	url = https://github.com/davechallis/xgboost
+	url = git@github.com:davechallis/xgboost
 	branch = v0.80-modified

xgboost-sys/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "xgboost-sys"
-version = "0.1.2"
+version = "0.2.0"
 authors = ["Dave Challis <[email protected]>"]
 links = "xgboost"
 build = "build.rs"