org-collector: enable specifying a default table-value as a parameter

* contrib/lisp/org-collector.el (org-dblock-write:propview): if a 'defaultval'
  property has been set, then use this in place of org-propview-default-value.

TINYCHANGE

contrib/lisp/org-collector.el

@@ -121,6 +121,7 @@ preceeding the dblock, then update the contents of the dblock."
 	    (scope (plist-get params :scope))
 	    (noquote (plist-get params :noquote))
 	    (colnames (plist-get params :colnames))
+	    (defaultval (plist-get params :defaultval))
 	    (content-lines (org-split-string (plist-get params :content) "\n"))
 	    id table line pos)
 	(save-excursion
@@ -133,9 +134,10 @@ preceeding the dblock, then update the contents of the dblock."
 		  (t (error "Cannot find entry with :ID: %s" id))))
 	  (unless (eq id 'global) (org-narrow-to-subtree))
 	  (setq stringformat (if noquote "%s" "%S"))
-	  (setq table (org-propview-to-table
-		       (org-propview-collect cols stringformat conds match scope inherit
-					     (if colnames colnames cols)) stringformat))
+	  (let ((org-propview-default-value (if defaultval defaultval org-propview-default-value)))
+	    (setq table (org-propview-to-table
+			 (org-propview-collect cols stringformat conds match scope inherit
+					       (if colnames colnames cols)) stringformat)))
 	  (widen))
 	(setq pos (point))
 	(when content-lines