(testsuite) Allow possibly leading whitespace in match_items() chunks > 1.

Thanks to Freddy Vulto.

test/lib/library.exp

@@ -503,7 +503,8 @@ proc match_items {items test {prompt /@} {size 20}} {
     set items [bash_sort $items]
     set result false
     for {set i 0} {$i < [llength $items]} {set i [expr {$i + $size}]} {
-        set expected ""
+            # For chunks > 1, allow leading whitespace
+        if {$i > $size} { set expected "\\s*" } else { set expected "" }
         for {set j 0} {$j < $size && $i + $j < [llength $items]} {incr j} {
             set item "[lindex $items [expr {$i + $j}]]"
                 # Escape special regexp characters