unify deps and more strict start and stop

deltachat-ffi/Cargo.toml

@@ -20,7 +20,7 @@ libc = "0.2"
 human-panic = "1.0.1"
 num-traits = "0.2.6"
 serde_json = "1.0"
-async-std = { git = "https://github.com/async-rs/async-std" }
+async-std = "1.6.0-beta.2"
 anyhow = "1.0.28"
 thiserror = "1.0.14"
 
@@ -28,3 +28,4 @@ thiserror = "1.0.14"
 default = ["vendored", "nightly"]
 vendored = ["deltachat/vendored"]
 nightly = ["deltachat/nightly"]
+

deltachat-ffi/src/lib.rs

@@ -1875,7 +1875,6 @@ pub unsafe extern "C" fn dc_imex(
         }
     };
 
-    // TODO: this is now blocking, figure out if that is okay
     let ffi_context = &*context;
 
     let param1 = to_opt_string_lossy(param1);