New test for another error case in DepositScriptAddress

Did you actually run the test with the change you're suggesting or are
you just trying to give me a hard time?

salgado@delgadito~/.../btcwallet/waddrmgr (vp *) $ git diff
diff --git a/waddrmgr/pool_test.go b/waddrmgr/pool_test.go
index ee7388c..d8c2e5a 100644
--- a/waddrmgr/pool_test.go
+++ b/waddrmgr/pool_test.go
@@ -273,6 +273,7 @@ func TestDepositScriptAddressFailureToEncrypt(t
*testing.T) {
                        _, err = pool.DepositScriptAddress(0, 0, uint32(1))
                })

+       err = nil
        checkManagerError(t, "", err, waddrmgr.ErrCrypto)
 }

salgado@delgadito~/.../btcwallet/waddrmgr (vp *) $  go test -run
TestDepositScriptAddressFailureToEncrypt ./
--- FAIL: TestDepositScriptAddressFailureToEncrypt-4 (0.05 seconds)
	common_test.go:47: : unexpected error type - got <nil>, want
waddrmgr.ManagerError
FAIL
FAIL	github.com/monetas/btcwallet/waddrmgr	0.053s