B2018-080 Don't break if HLS and High Level RNO each have one line of text and there are substeps (keep single line HSL and High Level RNO with their substeps)

B2018-080 NULL reference fix (was preventing a procedure from being printed)

PROMS/Volian.Print.Library/vlnParagraph.cs

@@ -2820,7 +2820,7 @@ namespace Volian.Print.Library
 					case E_ContBottomLoc.EndOfText:					// place continue string at end of text
 						// msg_yLocation accounts for extra lines in message from docstyle; and BottomContent is the actual 
 						// location of the last line of text on page.
-						msg_yLocation = msg_yLocation + ((float)MyPageHelper.BottomContent - (SixLinesPerInch * MyPageHelper.YMultiplier));
+						msg_yLocation = msg_yLocation + ((float)(MyPageHelper.BottomContent??0) - (SixLinesPerInch * MyPageHelper.YMultiplier)); // B2018-080 null reference check added
 						float tableSpaceAvailable = TableSpaceAvailable;// RHM20150525 - Table Scrunch
 						if (yBottomMargin + (docstyle.Layout.FooterLength ?? 0) > msg_yLocation)
 						{ // Adjusted Continue Message Y Offset