Fix absolute path resolution for child of child use-case

There is a typo in AbsolutePathResolver class, which resolves property absolute path from some other property path and relative path.
https://github.com/Talend/component-runtime/blob/9d2c482a2941df194f86e79bcd9dbc15cabd91ab/component-form/component-form-core/src/main/java/org/talend/sdk/component/form/internal/converter/impl/widget/path/AbsolutePathResolver.java#L51

This causes incorrect resolution for following use-case:
property path "dummy.foo"
relative path "./child/grandchild"
result it "dummy.foo.child/grandchild",
but should be "dummy.foo.child.grandchild"