Fix doc comment

Author: chipshort

x/wasm/types/wasmer_engine.go

@@ -278,8 +278,8 @@ type WasmEngine interface {
 	) (*wasmvmtypes.IBCBasicResult, uint64, error)
 
 	// IBCDestinationCallback is available on IBC-callbacks-enabled contracts and is called when an
-	// IBC-callbacks-enabled IBC message previously sent by this contract is either acknowledged or
-	// times out.
+	// IBC-callbacks-enabled IBC message previously sent from a different chain is being
+	// acknowledged on this chain.
 	IBCDestinationCallback(
 		checksum wasmvm.Checksum,
 		env wasmvmtypes.Env,