remove autoconversion, does not work in all cases properly

partly reverts commit c0243b9d2832535ac12bbd72f80d9150f256f8a8

autoconversion breaks tests, there is used list<any> with $[] (hash)
default value, when passing list<list> (e.g. [[map1, map2]]) then the conversion
fails as the index result is list not hash (as guessed from the type of the default)

(see Testsuite::Init() in Testsuite.ycp)