fix: cli: don't crash multicol with few strings

When there are only few, short strs and width is large, then the div
operation in itemspercol would return zero, triggering and error in
chunksOf.

This fix makes numcols have always at least as many entries as strs,
filling one line.

hledger/Hledger/Cli/Commands.hs

@@ -277,7 +277,7 @@ multicol _ [] = []
 multicol width strs =
   let
     maxwidth = maximum' $ map length strs
-    numcols = width `div` (maxwidth+2)
+    numcols = min (length strs) (width `div` (maxwidth+2))
     itemspercol = length strs `div` numcols
     colitems = chunksOf itemspercol strs
     cols = map unlines colitems