TS crashed with "NONE predicate can not be pushed into key"

tserver crashes on Scan when [lowerPrimaryKey, upperPrimary) and predicates of primary column do not overlap.

Example of table in TestScannerMultiTablet unittest, The table like this:

key1 (string) | key2 (string) | value (string)

The data layout ends up like this:

tablet '', '1': no rows
tablet '1', '2': '111', '122', '133'
tablet '2', '3': '211', '222', '233'
tablet '3', '': '311', '322', '333'

add Scan PrimaryKeyBounds: ['12', '13')

add Scan Predicate: key2 <= '1'

Run the example, ts will crash, and print "NONE predicate can not be pushed into key"