jss.layout: update appearance of 2 styles in LyX

This was proposed by the co-author of the layout in bug#9516

lib/layouts/jss.layout

@@ -44,20 +44,10 @@ Style Title
 	EndFont
 End
 
-Style "Plain Title"
-	CopyStyle			Title
-	LatexName			Plaintitle
-End
-
 Style Author
 	InPreamble			1
 End
 
-Style "Plain Author"
-	CopyStyle			Author
-	LatexName			Plainauthor
-End
-
 Style Abstract
 	Category			FrontMatter
 	LatexName			Abstract
@@ -120,12 +110,24 @@ Style "Plain Keywords"
 	LabelString			"Plain Keywords:"
 End
 
+Style "Plain Title"
+	CopyStyle			Keywords
+	LatexName			Plaintitle
+	LabelString			"Plain Title:"
+End
+
 Style "Short Title"
 	CopyStyle			Keywords
 	LatexName			Shorttitle
 	LabelString			"Short Title:"
 End
 
+Style "Plain Author"
+	CopyStyle			Keywords
+	LatexName			Plainauthor
+	LabelString			"Plain Author:"
+End
+
 InsetLayout "Flex:Pkg"
 	LyxType				custom
 	LabelString			pkg