Remove useTabs from sample Maven config in README
Remove useTabs from sample Maven config in README

The presence of this property causes a project set up with the sample configuration to fail:
detekt:
   [detekt] Was passed main parameter '--useTabs' but no main parameter was defined in your arg class
   [detekt] 
   [detekt] Usage: detekt [options]
   [detekt]   Options:
It looks like this property was removed in #326
Mauin/detekt,rock3r/detekt,arturbosch/detekt,Mauin/detekt,arturbosch/detekt,Mauin/detekt,arturbosch/detekt,rock3r/detekt,Mauin/detekt,rock3r/detekt