jsvn: ignore IOError writing to broken pipe when pager is exited

jsvn

@@ -449,4 +449,9 @@ def main(argv):
     return 0
 
 if __name__ == "__main__":
-    sys.exit(main(sys.argv[1:]))
+    rc = 0
+    try:
+        rc = main(sys.argv[1:])
+    except IOError:
+        pass
+    sys.exit(rc)