Change case insensitive search query

[rene78]

Currently when searching for places with multiple words (e.g. "frankfurt am main) case insensitivity is not covered for the second and subsequent words, thus nothing will be found. With the solution below this problem should be solved.

Use "i". See https://wiki.openstreetmap.org/wiki/Overpass_API/Overpass_QL#Case_insensitively

Example: node["name"~"^Foo$",i]; /* finds "foo", "FOO", "fOo", "Foo" etc. */