Update to libssh2-sys 0.3.0

Author: luqmana

libgit2-sys/Cargo.toml

@@ -22,7 +22,7 @@ path = "lib.rs"
 
 [dependencies]
 libc = "0.2"
-libssh2-sys = { version = "0.2.19", optional = true }
+libssh2-sys = { version = "0.3.0", optional = true }
 libz-sys = { version = "1.1.0", default-features = false, features = ["libc"] }
 
 [build-dependencies]