[201811 utilties] add 201811 branch for sonic-utilities repo

Submodule src/sonic-utilities d409987...ff1448c:
  > [sonic_installer] Improve error handling (sonic-net#460)
  > [clock] sync os time to CMOS before rebooting (sonic-net#465)
  < [sonic_installer] Improve error handling (sonic-net#460)
  < [clock] sync os time to CMOS before rebooting (sonic-net#465)
  < [intfstat] add intfstat script to output RIF counters (sonic-net#439)

Signed-off-by: Ying Xie <[email protected]>

Author: yxieca

.gitmodules

@@ -38,6 +38,7 @@
 [submodule "src/sonic-utilities"]
 	path = src/sonic-utilities
 	url = https://github.com/Azure/sonic-utilities
+	branch = 201811
 [submodule "platform/broadcom/sonic-platform-modules-arista"]
 	path = platform/broadcom/sonic-platform-modules-arista
 	url = https://github.com/aristanetworks/sonic