Remove index verification on opening BAM files

Currently, if an already built index it elder than the BAM file, then the index is automatically rebuilt by UGENE. This situation can be easily gained, if user downloads an assembly and its index, and index was downloaded first.
It is need to calculate time that is wasting on rebuilding an index, that is correct but too old. If the time is small enough, do nothing. If the time is perceptible, then remove the index validation.