Generic/OpeningBraceSameLine: improve code coverage

[rodrigoprimo]

Description

This PR improves the test code coverage for the Generic.Classes.OpeningBraceSameLine sniff. There was one line that was not exercised by tests that handle cases where the opening and closing brace for the class are on the same line as the class name.

Code coverage for this sniff before this PR:

https://coveralls.io/builds/64633848/source?filename=src%2FStandards%2FGeneric%2FSniffs%2FClasses%2FOpeningBraceSameLineSniff.php

And after this PR:

https://coveralls.io/builds/64729529/source?filename=src%2FStandards%2FGeneric%2FSniffs%2FClasses%2FOpeningBraceSameLineSniff.php

Related issues/external references

Part of #146

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
  • This change is only breaking for integrators, not for external standards or end-users.
• Documentation improvement

PR checklist

• I have checked there is no other PR open for the same change.
• I have read the Contribution Guidelines.
• I grant the project the right to include and distribute the code under the BSD-3-Clause license (and I have the right to grant these rights).
• I have added tests to cover my changes.
• I have verified that the code complies with the projects coding standards.
• [Required for new sniffs] I have added XML documentation for the sniff.

[jrfnl]

LGTM! Thanks @rodrigoprimo !