pylint: split command line argument on multiple lines

This clarify the important line in that configuration.

Differential Revision: https://phab.mercurial-scm.org/D1831

tests/test-check-pylint.t

@@ -11,7 +11,8 b' Current checks:'
 
   $ touch $TESTTMP/fakerc
   $ pylint --rcfile=$TESTTMP/fakerc --disable=all \
-  >   --enable=W0102 --reports=no \
+  >   --enable=W0102 \
+  >   --reports=no \
   >   --ignore=thirdparty \
   >   mercurial hgdemandimport hgext hgext3rd
    (?)