Fix: Ascent of peak index label in ascent viewer when no peak is set

Previously showed "0/-1", now "0/0"

Author: svetter

src/viewer/ascent_viewer.cpp

@@ -417,7 +417,7 @@ void AscentViewer::updateAscentNavigationTargets()
 	lastAscentOfPeakViewRowIndex		= ViewRowIndex();
 
 	currentAscentOfPeakIndex	= -1;
-	numAscentsOfPeak			= -1;
+	numAscentsOfPeak			= 0;
 
 	BufferRowIndex bufferRowIndex = compAscents->getBufferRowIndexForViewRow(currentViewRowIndex);
 	ItemID peakID = db->ascentsTable->peakIDColumn->getValueAt(bufferRowIndex);