Update pr.go to check if .Type is empty to avoid trying to create an empty label

[dougnukem]

Description

When creating a branch pattern where {{.Type}} is optional gh prx fails to create label with error:

⨯ Command failed                                     error=Failed to create labels: Failed to create label '': failed to run gh: HTTP 422: Validation Failed (https://api.github.com/repos/customerOrg/repoTest/labels)

branch:
   template: "{{.Type}}/{{with .Issue}}{{.}}-{{end}}{{.Description}}" # Branch name template
   pattern: "({{.Type}}|{{.Prefix}})\\/({{.Issue}}-)?{{.Description}}" # Branch name pattern
   variable_patterns: # A map of patterns to match for each template variable
      Type: "fix|feat|chore|docs|refactor|test|style|build|ci|perf|revert"
      # Branch name prefix like dougnukem/JIRAPROJ-XYZ-description-stuff
      Prefix: "[a-zA-Z0-9]+(?:-[a-zA-Z0-9]+)*"
      Issue: "([a-zA-Z]+\\-)*[0-9]+"
      Author: "[a-zA-Z0-9]+"
      Description: ".*"
   token_separators: ["-", "_"] # Characters used to separate branch name into a human-readable string
   max_length: 60 # Max characters to allow for branch length without prompting for changing it

[ilaif]

Thanks for fixing that! LGTM

[ilaif]

@dougnukem there's a new linter I added that handles complexity in if blocks. It might be too sensitive but you can try refactor to a guard-clause to remove the complexity.