switch to stable toolchain by default

Cargo.toml

@@ -90,7 +90,7 @@ required-features = ["repl"]
 
 
 [features]
-default = ["nightly"]
+default = []
 internals = []
 repl = ["internals", "rustyline", "log", "pretty_env_logger", "ansi_term"]
 vendored = ["async-native-tls/vendored", "async-smtp/native-tls-vendored"]

deltachat-ffi/Cargo.toml

@@ -25,7 +25,7 @@ anyhow = "1.0.28"
 thiserror = "1.0.14"
 
 [features]
-default = ["vendored", "nightly"]
+default = ["vendored"]
 vendored = ["deltachat/vendored"]
 nightly = ["deltachat/nightly"]
 

rust-toolchain

@@ -1 +1 @@
-nightly-2020-03-19
+1.43.1