[pgAdmin4][patch] fix a typo in import_export_servers.rst

[zhangj...@fujitsu.com]

Hi, all

It seems like there's a following typo in import_export_servers.rst
-line option. There can be multiple configuations of pgAdmin on the same system.
+line option. There can be multiple configurations of pgAdmin on the same 
system.

Attaching a tiny patch to fix it. 
Please review.

Regards,
zhang jie

--------------------------------------------------
Development Department III
Software Division II
Nanjing Fujitsu Nanda Software Tech. Co., Ltd.(FNST)
No.6 Wenzhu Road, Software Avenue, Nanjing, 210012, China
TEL  : +86+25-86630566-9353
COINS: 7998-9353
FAX  : +86+25-83317685
MAIL: zhangj...@fujitsu.com
FNST Oline：http://online.fnst.cn.fujitsu.com/fnst-news
-------------------------------------------------

import_export_servers.patch
Description: import_export_servers.patch