[Bug] Paths.sanitizeRequestMappingPattern fix

[nobe0716]

Paths.sanitizeRequestMappingPattern works wrong with multi path variable between slashes
I copied java from source and changed regex to "\{([^}]+?):([^/{}]|\{[\d,]+\})+\}".

• Version: v2.7.0
• Gist: https://gist.github.com/nobe0716/93a949afb91a73730566d7a7b50cb4b1
• ApiDescriptionReaderSpec should add new test case

  def "should sanitize request mapping endpoints"() {
    expect:
    Paths.sanitizeRequestMappingPattern(mappingPattern) == expected

    where:
    mappingPattern                                  | expected
    "/{businessId:\\d{3}}:{productId:\\D{3}\\d{3}}" | "/{businessId}:{productId}"
  }