fix: missing from field in brick.yml -> panic module.LoadAvailable action nil pointer dereference

[arthur91f]

$ exeiac lay apps/database
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x575729]

goroutine 1 [running]:
src/exeiac/infra.(*Module).LoadAvailableActions(0x5b0f20?)
/home/arthur91f/git/exeiac/src/infra/module.go:68 +0x29
src/exeiac/infra.(*Infra).EnrichBricks(0xc0000c8a00)
/home/arthur91f/git/exeiac/src/infra/enrichBricks.go:233 +0x19c
main.main()
/home/arthur91f/git/exeiac/src/main.go:73 +0x69e

It was resolve by correcting brick.yml of apps/myapp/configuration. A field from was let empty.
A brick.yml conf error shouldn't block exeiac if the brick will not be executed. Moreover we should avoid panic.