Fix results from baloorunner when query starts with =
This fixes Bug 345134
Queries starting with = should trigger the calculator, but the AdvancedQueryParser::parse method in baloo interpreted it as an operator.
This can also be reproduced with the CLI:
baloosearch "1+1+1" -t Video
No Results
baloosearch "=1+1+1" -t Video
A lot of results