[submodule]: update sonic-utilities (#6681)

* 28d358f 2021-02-01 | [show] Run fwutil with sudo (#1364) (HEAD) [Volodymyr Boiko]
* a50b7a2 2021-01-29 | [ecnconfig] Allow ecn unit test to run without sudo (#1390) [Neetha John]
* 8a1109e 2021-01-29 | [sonic-installer] Add information to syslog (#1369) [Dmytro]
* c7c01e4 2021-01-27 | [show] fix "show interfaces breakout" command (#1198) [Dmytro Shevchuk]
* 7a8024a 2021-01-27 | Prevent user from adding more then a single untagged VLAN to an interface (#1382) [Eran Dahan]
* 41e62c6 2021-01-26 | [pcieutil] Add 'pcie-aer' sub-command to display AER stats (#1169) [Arun Saravanan Balachandran]
* 47f412b 2021-01-25 | Improve robustness of consutil plugin loading (#1353) [Samuel Angebault]
* 64aa1b8 2021-01-26 | [show] Fix warnings, related to gearbox, while show commands execution (#1343) [maksymbelei95]
* ff226d0 2021-01-25 | Prevent configuring IP interface on a port which is a member of VLAN (#1374) [Eran Dahan]
* f1522b9 2021-01-21 | [config_mgmt.py]: Set leaf-list to empty list while port breakout. (#1268) [Praveen Chaudhary]
* 99c05d5 2021-01-21 | add vlan_intf_object only if there are ipv4 or ipv6 mappings (#1377) [Sumukha Tumkur Vani]
* b082684 2021-01-21 | [ecn] Add tests for ecnconfig command (#1372) [Neetha John]
* 23e0920 2021-01-21 | [sfpshow] Enhance QSFP-DD DOM information (#1207) [shlomibitton]
* f4edba1 2021-01-20 | [ecnconfig] handle backend port names when extracting port I/F ID from the port name (#1361) [Mahesh Maddikayala]

Signed-off-by: Guohan Lu <lguohan@gmail.com>