ui: don't switch profile when the prepared chat failed to move

ComposeContextProfilePickerView.changeProfile called changeActiveUser_
outside both 'updated != null' branches, so when
apiChangePreparedContactUser or apiChangePreparedGroupUser returned null
the chat stayed on the old profile but the active user was switched
anyway - and the post-switch check passed, so no error was shown either.
The invitation is then left behind on a profile the user is no longer on.

Kotlin only: the iOS twin throws instead of returning null, so its outer
catch already skips the switch.

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/ComposeContextProfilePickerView.kt

@@ -79,6 +79,7 @@ fun ComposeContextProfilePickerView(
 
   fun changeProfile(newUser: User) {
     withApi {
+      var chatMoved = false
       if (chat.chatInfo is ChatInfo.Direct) {
         val updatedContact = chatModel.controller.apiChangePreparedContactUser(rhId, chat.chatInfo.contact.contactId, newUser.userId)
         if (updatedContact != null) {
@@ -86,6 +87,7 @@ fun ComposeContextProfilePickerView(
           chatModel.controller.appPrefs.incognito.set(false)
           listExpanded.value = false
           chatModel.chatsContext.updateContact(rhId, updatedContact)
+          chatMoved = true
         }
       } else if (chat.chatInfo is ChatInfo.Group) {
         val updatedGroup = chatModel.controller.apiChangePreparedGroupUser(rhId, chat.chatInfo.groupInfo.groupId, newUser.userId)
@@ -94,8 +96,10 @@ fun ComposeContextProfilePickerView(
           chatModel.controller.appPrefs.incognito.set(false)
           listExpanded.value = false
           chatModel.chatsContext.updateGroup(rhId, updatedGroup)
+          chatMoved = true
         }
       }
+      if (!chatMoved) return@withApi
       chatModel.controller.changeActiveUser_(
         rhId = newUser.remoteHostId,
         toUserId = newUser.userId,