Implement simpler fix for emote completion bug

This commit implements a simpler fix for the problem described in #1209.
The setting's signal is connected to a reset of `completionInProgress_`
so that the completion model is updated on the next word already.

This commit also removes the older approach tackling this issue.

src/widgets/helper/ResizingTextEdit.cpp

@@ -16,6 +16,11 @@ ResizingTextEdit::ResizingTextEdit()
     QObject::connect(this, &QTextEdit::textChanged, this,
                      &QWidget::updateGeometry);
 
+    // Whenever the setting for emote completion changes, force a
+    // refresh on the completion model the next time "Tab" is pressed
+    getSettings()->prefixOnlyEmoteCompletion.connect(
+        [this] { this->completionInProgress_ = false; });
+
     this->setFocusPolicy(Qt::ClickFocus);
 }
 
@@ -260,11 +265,6 @@ void ResizingTextEdit::insertFromMimeData(const QMimeData *source)
     }
 }
 
-void ResizingTextEdit::resetCompletionInProgress()
-{
-    this->completionInProgress_ = false;
-}
-
 QCompleter *ResizingTextEdit::getCompleter() const
 {
     return this->completer_;