Fix duplicated addresses
Summary
Occasionally Android spits duplicates at us
See: https://bugs.kde.org/show_bug.cgi?id=415881
BUG 415531
Test Plan
Before:
Load a single-target conversation in which the last-received message was an RCS, observe that the conversation appears to be a group conversation with the same person twice.
After:
Single-target conversations should appear as single-target conversations.
Edited by Simon Redman