`$highestRow = $this->getHighestDataRow();` was calculated after `$this->getCellCollection()->removeRow($pRow + $r);` - this is the root reason for incorrect rows removal because removing last row will change '$this->getHighestDataRow()' value, but removing row from the middle will not change it. So, removing last row causes incorrect `$highestRow` value that is used for wiping out empty rows from the bottom of the table:
```php
for ($r = 0; $r < $pNumRows; ++$r) {
$this->getCellCollection()->removeRow($highestRow);
--$highestRow;
}
```
To prevent this incorrect behavior I've moved highest row calculation before row removal.
But this still doesn't solve another problem when trying remove non existing rows: in this case the code above will remove `$pNumRows` rows from below of the table, e.g. if `$highestRow=4` and `$pNumRows=6`, than rows 4, 3, 2, 1, 0, -1 will be deleted. Obviously, this is not good, that is why I've added `$removedRowsCounter` to fix this issue.
And finally, moved Exception to early if statement to get away from unnecessary 'if-else'.
Fixes#1364Closes#1365