Dry element suppression in stbtel leads to crash

An old cleaning action (in 2014) removed by error 3 important lines in elmpb.f. This was in commit 29055be7

       DO IEL = 1, NELEM
        ISDRY(IKLE(IEL,1)) = IKLE(IEL,1)
        ISDRY(IKLE(IEL,2)) = IKLE(IEL,2)
        ISDRY(IKLE(IEL,3)) = IKLE(IEL,3)
       ENDDO

became

       DO IEL = 1, NELEM
       ENDDO

This was not pointed by validation test case but this arise if you change the value of DRY LIMIT to 2.8 in selafin example. Probably because in this case you have a connected island.