SMB storage backend must not contact server in constructor

[PVince81]

Steps

1. Edit "tests/enable_all.php" and add the "files_external" app
2. Run ./autotest.sh sqlite apps/files_external/tests/mountconfig.php

Expected result

Config tests pass

Actual result

Even though only the constructor of the \OC\Files\SMB class is called, it still tries to make a connection:

.FF..Can't contact server smbhost. Error NT_STATUS_UNSUCCESSFUL
FCan't contact server smbhost. Error NT_STATUS_UNSUCCESSFUL
(...snip...)
FCan't contact server somehost. Error NT_STATUS_UNSUCCESSFUL
FF

Versions

ownCloud 8.1 git master

After debugging I found that the SMB library from @icewind1991 tries to load the timezone from the server.

@icewind1991 can you fix it to do this lazily ?
External storage classes must not attempt any connection from the constructor, because it will cause other (future) problems like when deleting storages, see #11694

[PVince81]

It was actually on this branch: #11884

It looks like on master someone removed the name "SMB" to make it work.

Still, would be good to fix this eventually.

[DeepDiver1975]

@PVince81
@Xenopathic recently replaced the smb storage with Test_Mount_Config_Dummy_Storage
https://github.com/owncloud/core/blob/master/apps/files_external/tests/mountconfig.php#L24

To make the unit tests pass properly - just FYI - lazy ctor is still desired