[FIX] rml: avoid reports ending by zero (opw 608073)

Commit b6a7402f (reverted at f8671cb4) was almost correct, the PageReset should be added at the end of each stories but only if we have one more stories.
The PageReset will force the page count to be reseted at zero which means that last page of report would have been at zero.

openerp/report/render/rml2pdf/trml2pdf.py

@@ -999,10 +999,10 @@ class _rml_template(object):
         story_cnt = 0
         for node_story in node_stories:
             if story_cnt > 0:
+                # Reset Page Number with new story tag
+                fis.append(PageReset())
                 fis.append(platypus.PageBreak())
             fis += r.render(node_story)
-            # Reset Page Number with new story tag
-            fis.append(PageReset())
             story_cnt += 1
         try:
             if self.localcontext and self.localcontext.get('internal_header',False):