testsh?.sh: fix sort(1) invocations

Newly imported sort(1) works slightly differently. In fact, the old
sort(1) had a bug and the tests invoked sort(1) the wrong way.

test/testsh1.sh

@@ -229,7 +229,7 @@ sort <x >x1
 if cmp -s y x1; then : ; else echo Error on sort test 2; fi
 sort -r <x1 >x2
 if cmp -s x2 z; then : ; else echo Error on sort test 3; fi
-sort +1 -n <x |head -1 >y
+sort -k 2n <x |head -1 >y
 echo "bibelot 3" >z
 if cmp -s y z; then : ; else echo Error on sort test 4; fi
 

test/testsh2.sh

@@ -247,7 +247,7 @@ cat >answer <<END
 END
 
 prep x | sort | uniq -c >y1
-sort +1 <y1 >y
+sort <y1 >y
 if cmp -s y answer; then : ; else echo Error in pipeline test 1; fi
 
 cat $f $f $f | sort | uniq >x