upgrade oauth2

Author: Heliozoa

tmc-client/Cargo.toml

@@ -13,7 +13,7 @@ chrono = { version = "0.4", features = ["serde"] }
 dirs = "3"
 http = "0.2"
 log = "0.4"
-oauth2 = { version = "4.0.0-beta.1", features = ["reqwest"] }
+oauth2 = { version = "4", features = ["reqwest"] }
 once_cell = "1"
 percent-encoding = "2"
 regex = "1"