Cannot add example tag containing double colon (":")

[GusAntoniassi]

Describe the bug
The following struct fails to generate the docs through swag init:

type Foo struct {
  Attributes map[string]string `example:"bucket_arn:arn:aws:::foobar-bucket"`
}

The following error is returned:

ParseComment error in file /tmp/foobar/main.go :example value bucket_arn:arn:aws:::foobar-bucket should format: key:value

Escaping the value with double backlashes (\\) does not work.

To Reproduce
Steps to reproduce the behavior:

1. Create the following main.go file:

package main

type Resource struct {
        Attributes    map[string]string `example:"bucket_arn:arn:aws:::foobar-bucket"`
}

//      @Summary                Foo
//      @Success                200     {object}        Resource
//      @Router                 /foo [get]
func main() {

}

2. Generate the docs with swag init ./main.go

Expected behavior
Users should be able to create examples with double colons, maybe escaping them with double backlashes to avoid key:value conflicts.

Your swag version
1.8.8

Your go version
e.g. 1.19.3

Desktop (please complete the following information):

• OS: Linux
• Browser: Not relevant