Improve checking time span for voting KF

src/processor/processor_imu.cpp

@@ -49,7 +49,7 @@ void ProcessorImu::preProcess()
 bool ProcessorImu::voteForKeyFrame() const
 {
     // time span
-    if (getBuffer().back().ts_ - getBuffer().front().ts_ > params_motion_Imu_->max_time_span - params_motion_Imu_->time_tolerance)
+    if (getBuffer().back().ts_ - getBuffer().front().ts_ >= params_motion_Imu_->max_time_span - Constants::EPS)
     {
         WOLF_DEBUG( "PM: vote: time span" );
         return true;