Let columnline_style default to none

Change-Id: Icbeed54325cfd8ff36005da124a556af72435413
diff --git a/inst/rmarkdown/templates/posterdown_ids/resources/template.html b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
index dd55a19..de99327 100644
--- a/inst/rmarkdown/templates/posterdown_ids/resources/template.html
+++ b/inst/rmarkdown/templates/posterdown_ids/resources/template.html
@@ -154,9 +154,9 @@
 -webkit-column-rule-width: $if(columnline_width)$$columnline_width$$else$1mm$endif$;
 -moz-column-rule-width: $if(columnline_width)$$columnline_width$$else$1mm$endif$;
 column-rule-width: $if(columnline_width)$$columnline_width$$else$1mm$endif$;
--webkit-column-rule-style: $if(columnline_style)$$columnline_style$$else$dashed$endif$;
--moz-column-rule-style: $if(columnline_style)$$columnline_style$$else$dashed$endif$;
-column-rule-style: $if(columnline_style)$$columnline_style$$else$dashed$endif$;
+-webkit-column-rule-style: $if(columnline_style)$$columnline_style$$else$none$endif$;
+-moz-column-rule-style: $if(columnline_style)$$columnline_style$$else$none$endif$;
+column-rule-style: $if(columnline_style)$$columnline_style$$else$none$endif$;
 -webkit-column-rule-color: $if(columnline_col)$$columnline_col$$else$$if(primary_colour)$$primary_colour$$else$#f57c14$endif$$endif$;
 -moz-column-rule-color: $if(columnline_col)$$columnline_col$$else$$if(primary_colour)$$primary_colour$$else$#f57c14$endif$$endif$;
 column-rule-color: $if(columnline_col)$$columnline_col$$else$$if(primary_colour)$$primary_colour$$else$#f57c14$endif$$endif$;