[Submodule]: update sonic-restapi (#10295)

[Submodule]: update sonic-restapi
bd97dfe Fix urllib3 CVE-2021-33503 issue (#104)
f159bfa Upgrade the containers to be based on Debian Buster (#103)
a1830c1 Fix OpenAPI spec to be readable by autorest (#101)
94805a3 Identify and report Vnet GUID for conflicting VNI (#99)
4832dfd Static route expiry if not specified as persistent (#98)
5cc4358 Add support for overlay ECMP (#96)
6822a46 [CI] Set diff cover threshold to 50% (#97)
dcc826a Add PR diff coverage (#95)
e842c5f Generate code coverage for Unit Tests (#94)
f9bbed3 Convert Unit Tests from unittest framework to pytest framework (#93)
e466ac2 Reject incorrect CIDR addresses while configuring routes (#91)
07cf59d [CI] Set up Azure pipeline (#89)
47476ac Upgrade Go version to 1.14 (#90)
ee887c7 Added flag to make go/pkg/ folder writable (removable) (#87)
6cfc8fe (origin/shilongliu/azp) Default Vrf static route support (#85)
d3e8b8e Add BFD config to subinterface and neighbor (#68)
8d4fd4a Fix WS-2018-0594 potential non-random UUIDs security issue (#78)
fad87fa Update API description for default vrf and ecmp routes (#82)

Some of them have been updated in 202012 branch, should be added in 202106 as well.