UI: Fix projector connecting the wrong source signal

The signal name is "remove" for when a source is removed, not "removed".

This is proof that I should never have relied on strings for signals.
The original intention for string-based signals was to make them
programmable and scriptable, but honestly that use-case (that never
happened and will likely never happen) was foolish to program around.
These should have been fixed macros from the beginning.

obs/window-projector.cpp

@@ -12,7 +12,7 @@ OBSProjector::OBSProjector(QWidget *widget, obs_source_t *source_)
 	                                Qt::Window | Qt::FramelessWindowHint),
 	  source                       (source_),
 	  removedSignal                (obs_source_get_signal_handler(source),
-	                                "removed", OBSSourceRemoved, this)
+	                                "remove", OBSSourceRemoved, this)
 {
 	setAttribute(Qt::WA_DeleteOnClose, true);