Upgrade RuboCop to >= 1.30.1

RuboCop v1.30.1 fixed a false positive for Style/SafeNavigation

Author: mishina2228

.rubocop_todo.yml

@@ -126,16 +126,6 @@ Style/MultipleComparison:
 Style/NumericLiterals:
   MinDigits: 20
 
-# Offense count: 4
-# This cop supports safe autocorrection (--autocorrect).
-# Configuration parameters: ConvertCodeThatCanStartToReturnNil, AllowedMethods, MaxChainLength.
-# AllowedMethods: present?, blank?, presence, try, try!
-Style/SafeNavigation:
-  Exclude:
-    - 'benchmark/setup_db.rb'
-    - 'ext/mysql2/extconf.rb'
-    - 'lib/mysql2/em.rb'
-
 # Offense count: 14
 # This cop supports unsafe autocorrection (--autocorrect-all).
 # Configuration parameters: Mode.

Gemfile

@@ -17,7 +17,7 @@ group :test do
   gem 'rspec', '~> 3.2'
 
   # https://github.com/bbatsov/rubocop/pull/4789
-  gem 'rubocop', '~> 1.30' if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.6')
+  gem 'rubocop', '~> 1.30', '>= 1.30.1' if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.6')
 end
 
 group :benchmarks, optional: true do