obsolete: change warning output to match mercurial core on
The new messages were introduced by hg@12fdaa30063a.
6c6bb7a23bb5125bf06da73265f039dd3447dafa 0.1.0
d3f20770b86a31dba56ae7b252089e12b34702da 0.2.0
c046b083a5e0b21af69027f31cee141800cf894b 0.3.0
9bbcd274689829d9239978236e16610688978233 0.4.0
4ecbaec1d664b1e6f8ebc78292e1ced77a8e69c0 0.4.1
7ef8ab8c6feadb8a9d9e13af144a17cb23e9a38d 0.5