Fix an incorrect autocorrect for Style/BracesAroundHashParameters

[koic]

Fixes rubocop/rubocop-jp#45. (This link is Japanese issue)

This PR fixes an incorrect autocorrect for Style/BracesAroundHashParameters when the opening brace is before the first hash element.

% rubocop -V
0.60.0 (using Parser 2.5.1.2, running on ruby 2.5.1 x86_64-darwin17)

% cat example.rb
# frozen_string_literal: true

foo = Foo.new(
  { foo: 'foo',
    bar: 'bar',
    baz: 'this is the last element'}
)

The following difference is the execution result of rubocop -a command.

Before

The last element is lost.

diff --git a/example.rb b/example.rb
index ecf9711..c9a02b8 100644
--- a/example.rb
+++ b/example.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true

 foo = Foo.new(
-  { foo: 'foo',
-    bar: 'bar',
-    baz: 'this is the last element'}
+  foo: 'foo',
+  bar: 'bar'
 )

After

Remove only the braces.

diff --git a/example.rb b/example.rb
index ecf9711..57790da 100644
--- a/example.rb
+++ b/example.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true

 foo = Foo.new(
-  { foo: 'foo',
-    bar: 'bar',
-    baz: 'this is the last element'}
+  foo: 'foo',
+  bar: 'bar',
+  baz: 'this is the last element'
 )

---

Before submitting the PR make sure the following are checked:

• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• The PR relates to only one subject with a clear title
  and description in grammatically correct, complete sentences.
• Run rake default. It executes all tests and RuboCop for itself, and generates the documentation.

[koic]

To correct this indentation gap, the opening brace must be replaced with space instead of being removed.

First of all, this PR solves the problem that last element is lost by auto-correct. I'm considering solving this indentation gap problem with another PR.

Until then this indetation gap will be aligned with Layout/AlignHash cop.

[bbatsov]

👍