qt: Avoid test failure when test is run multiple times
* lang/qt/tests/t-import.cpp (ImportTest): Add member tempGpgHome and member function initTestCase. (keyFpr, keyData): Move to ImportTest::testImportWithKeyOrigin.
Use different temporary GNUPGHOME's when running the test. This ensures
that the import in the test is always done with a new keyring.
- GnuPG-bug-id: T5733