raco exe: fix section alignment for PE rewriting

A new resource section was aligned based on the old section's
virtual address, instead of the PE's specified section
alignment. That could make alignment round up too far, leaving
a disallowed gap in the sections' virtual addresses.

racket/collects/compiler/private/pe-rsrc.rkt

@@ -454,7 +454,7 @@
 
     (define new-virtual-addr
       (same-alignment
-       (section-virtual-addr s)
+       (pe-section-alignment pe)
        (for/fold ([pos 0]) ([s2 (in-list (pe-sections pe))]
                             #:unless (eq? s s2))
          (max pos