[.editorconfig] Don't trim trailing whitespace

There is so much of it everywhere that opening any file
in the project ends up creating large diffs which have
nothing to do with the changes, test files are especially
affected by this.

Author: xedin

.editorconfig

@@ -5,5 +5,5 @@ root = true
 [*]
 indent_style = space
 indent_size = 2
-trim_trailing_whitespace = true
+trim_trailing_whitespace = false
 insert_final_newline = true