async-tungstenite: Make TLS features optional (#222)

* async-tungstenite: Make TLS features optional

The included TLS features are only required for wss connections to the mailbox
server which not required by the protocol and only really useful for wasm
builds.

Closes #216

Author: felinira

Cargo.lock

@@ -63,10 +63,7 @@ tar = { version = "0.4.33", optional = true }
 [target.'cfg(not(target_family = "wasm"))'.dependencies]
 libc = "0.2.101"
 async-std = { version = "1.12.0", features = ["attributes", "unstable"] }
-async-tungstenite = { version = "0.25", features = [
-    "async-std-runtime",
-    "async-tls",
-] }
+async-tungstenite = { version = "0.25", features = ["async-std-runtime"] }
 async-io = "2.2.0"
 
 # Transit
@@ -103,6 +100,11 @@ forwarding = ["transit", "rmp-serde"]
 default = ["transit", "transfer"]
 all = ["default", "forwarding"]
 
+# TLS implementations for websocket connections via async-tungstenite
+# required for optional wss connection to the mailbox server
+tls = ["async-tungstenite/async-tls"]
+native-tls = ["async-tungstenite/async-native-tls"]
+
 [profile.release]
 overflow-checks = true
 strip = "debuginfo"