fix: Ensure protocol slashes are preserved in getSanitizedPath

[sanhee]

Description

When using WebClient with UriBuilder to construct URIs, I encountered a problem where a protocol's double slashes (://) were incorrectly reduced to a single slash (:/).
This behavior was traced back to the getSanitizedPath method, which removed redundant slashes without preserving the protocol structure.

Changes

• Refined logic to ensure protocol slashes are preserved.
• Cleaned up redundant slashes in the path without affecting the protocol.

Test

• To validate and fix this behavior, I tested the private getSanitizedPath method using reflection.
  • Since the method is private and part of an internal class, reflection was necessary to access and evaluate its behavior in isolation.
• Verified with multiple inputs, including paths with and without protocols, to ensure correct behavior.

AS-IS (Existing Issue)	TO-BE (Fixed Behavior)

Example Test Case

Input: http://example.com//path/to//resource
Output: http://example.com/path/to/resource

Input: https://example.com//path
Output: https://example.com/path

Input: example.com//path
Output: example.com/path