Produce n=2 when ports are not capped

[jaclark5]

PR Summary:

Resolves #1068

PR Checklist

---

• [NA] Includes appropriate unit test(s)
• [NA] Appropriate docstring(s) are added/updated
• Code is (approximately) PEP8 compliant
• Issue(s) raised/addressed?

[daico007]

LGTM! Thank you for the PR!

[codecov]

Codecov Report

Base: 90.51% // Head: 90.49% // Decreases project coverage by -0.01% ⚠️

Coverage data is based on head (419f988) compared to base (82977a2).
Patch coverage: 0.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1069      +/-   ##
==========================================
- Coverage   90.51%   90.49%   -0.02%     
==========================================
  Files          61       61              
  Lines        6156     6157       +1     
==========================================
  Hits         5572     5572              
- Misses        584      585       +1     

Impacted Files	Coverage Δ
mbuild/lib/recipes/alkane.py	38.88% <0.00%> (-0.74%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.