Update to Rust 1.51.0 and remove 1.47.0

Signed-off-by: Khem Raj <raj.khem@gmail.com>

recipes-devtools/cargo/cargo-1.51.0/0001-Disable-http2.patch

@@ -0,0 +1,28 @@
+From 9844e63845da6cdafa485ad1ad3c99eaaa80312d Mon Sep 17 00:00:00 2001
+From: Johan Anderholm <johan.anderholm@gmail.com>
+Date: Sun, 27 Jan 2019 10:19:00 +0100
+Subject: [PATCH] Disable http2
+
+http2 requires that curl is build with nghttp2 which in turn depends on
+many dependencies and ultimately a dependency loop in the case of
+curl-native. As long as multiplexing is disabled in cargo this should
+be fine.
+
+Upstream-Status: Inappropriate
+---
+ Cargo.toml | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/Cargo.toml b/Cargo.toml
+index 8a144a4..c4f856e 100644
+--- a/Cargo.toml
++++ b/Cargo.toml
+@@ -25,7 +25,7 @@ cargo-platform = { path = "crates/cargo-platform", version = "0.1.1" }
+ crates-io = { path = "crates/crates-io", version = "0.33.0" }
+ crossbeam-utils = "0.8"
+ crypto-hash = "0.3.1"
+-curl = { version = "0.4.23", features = ["http2"] }
++curl = { version = "0.4.23" }
+ curl-sys = "0.4.22"
+ env_logger = "0.8.1"
+ pretty_env_logger = { version = "0.4", optional = true }