HDRMerge: use action_images to allow merging a selected group

Author: ElectronicRU

contrib/HDRMerge.lua

@@ -219,7 +219,7 @@ local function main()
     dt.print(_('HDRMerge install issue, please ensure the binary path is correct'))
     return
   end
-  images = dt.gui.selection() --get selected images
+  images = dt.gui.action_images --get selected images
   if #images < 2 then --ensure enough images selected
     dt.print(_('not enough images selected, select at least 2 images to merge'))
     return
@@ -483,4 +483,4 @@ script_data.restart = restart
 script_data.destroy_method = "hide"
 script_data.show = restart
 
-return script_data
+return script_data