Truncate fetched buildSha if it is longer than the one we get from git log
Created by: rafax
https://sourcegraph.com/__version returns 124976_2022-01-11_49efaad8e7da01f5d974c36763055e6bfb1a722d
as current version, which caused a slice overflow in sg live
(that expects 10 char long sha).
Error
panic: runtime error: slice bounds out of range [:40] with length 10
goroutine 1 [running]:
main.printDeployedVersion({{0x1057d1bf9, 0x5}, {0x1057e8771, 0x17}})
/Users/rafal/dev/sourcegraph/dev/sg/live.go:113 +0x149c