Extend min panel width to eliminate text clipping

Change size policy of "Start Virtual Camera" button to ensure the
minimum width of `Controls` panel is the same as "Start Virtual
Camera" button plus the gear (settings) icon, therefore to
eliminate text clipping when overflow.

UI/window-basic-main.cpp

@@ -1938,6 +1938,8 @@ void OBSBasic::AddVCamButton()
 			    QStringLiteral("configIconSmall"),
 			    &OBSBasic::VCamConfigButtonClicked);
 	vcamButton->insert(2);
+	vcamButton->first()->setSizePolicy(QSizePolicy::Minimum,
+					   QSizePolicy::Minimum);
 }
 
 void OBSBasic::ResetOutputs()