better rewording in incoming msg procedure

Author: Ivansete-status

standards/application/reliable-channel-api.md

@@ -170,7 +170,7 @@ When a segment is received from the network, the implementation MUST process it
 
 1. **Decrypt**: If an `Encryption` implementation is provided, decrypt the segment.
 2. **Apply [SDS](https://lip.logos.co/ift-ts/raw/sds.html)**: Deliver the segment to the SDS layer, which emits acknowledgements and detects gaps.
-   - **Detect missing dependencies and fetch from store**: If SDS detects a gap in the causal history (i.e., a referenced predecessor segment has not yet been received), and considers the message is irretrievably lost, 
+   - **Detect missing dependencies and fetch from store**: If SDS detects a message in the causal history which has not yet been received , and considers the message is irretrievably lost, 
    the implementation MUST attempt to retrieve the missing segment throughout store protocol (store API is never exposed and hence, store queries are handled internally).
 3. **Reassemble**: Once all segments for a message have been received, reassemble and emit a `reliable:message:received` event.