Prefer doing less

The require_relative does not need to examine entries in the $LOAD_PATH
and its length does not affect lookup performance.

Author: mostlyobvious

lib/protobuf_nested_struct.rb

@@ -4,8 +4,8 @@
 require "google/protobuf"
 require "google/protobuf/well_known_types"
 
-require "protobuf_nested_struct/version"
-require "protobuf_nested_struct/struct_pb"
+require_relative "protobuf_nested_struct/version"
+require_relative "protobuf_nested_struct/struct_pb"
 
 module ProtobufNestedStruct
   class Value