Creating a new Dash when there's an "assets/” folder at the working directory results in cryptic warning messages

[daattali]

Create a directory named assets and don't place any files inside it. Then run dash::Dash$new() to see the following messages:

Warning messages:
1: In max.default(numeric(0), na.rm = TRUE) :
  no non-missing arguments to max; returning -Inf
2: In modtimeFromPath(private$assets_folder, recursive = TRUE) :
  NAs introduced by coercion to integer range