Don't insert closing brackets if character under cursor is not a space.

[aesilevich]

Example code:

func foo() {
  let x = 10
  x
}

How to reproduce:

1. Move cursor before the 'x' character at line 3
2. Insert the 'b', 'a', 'r', '(' characters.

After step 2, the result will be the following:

func foo() {
  let x = 10
  bar()x
}

The line 3 should be "bar(x".