run-tests: patch over py2.4 proc.wait() race

tests/run-tests.py

@@ -838,7 +838,11 b' def run(cmd, wd, options, replacements, '
         cleanup()
         raise
 
-    ret = proc.wait()
+    try:
+        ret = proc.wait()
+    except OSError:
+        # Py2.4 seems to have a race here
+        pass
     if wifexited(ret):
         ret = os.WEXITSTATUS(ret)