css: rename '.jt_workspace' to '.amber_workspace'

css/amber.css

@@ -270,7 +270,7 @@ body.amberBody {
 }
 
 .amberTool .amber_transcript,
-.amberTool .jt_workspace {
+.amberTool .amber_workspace {
     width: 100%;
     height: 100%;
 }