[tt] misinterprets the relative path to the templates folder

Steps to reproduce:

1. Init tt in the folder inside your home directory (cd /home/d/git && tt init)
2. Set relative path to the templates folder in the /home/d/git/tt.yaml (~/git/repo/templates/tt)
3. Try to create new app with template (tt create tdg --name tt_tdg_app)
4. Got error template 'tdg' is not found

d@m1book8715:~/git$ tt cfg dump
/home/d/git/tt.yaml:
tt:
  modules:
    directory: /home/d/git/modules
  app:
    run_dir: /home/d/git/var/run
    log_dir: /home/d/git/var/log
    log_maxsize: 100
    log_maxage: 8
    log_maxbackups: 10
    restart_on_failure: false
    wal_dir: /home/d/git/var/lib
    memtx_dir: /home/d/git/var/lib
    vinyl_dir: /home/d/git/var/lib
    bin_dir: /home/d/git/bin
    inc_dir: /home/d/git/include
    instances_enabled: /home/d/git/instances.enabled
    tarantoolctl_layout: false
  ee:
    credential_path: ""
  templates:
  - path: /home/d/git/~/git/repo/templates/tt
  repo:
    rocks: ""
    distfiles: /home/d/git/distfiles

Expected behavior:

• Relative paths works correctly

Reproduce the issue with tt init, the relative templates path in tt.yaml, and tt create, then compare the configured path shown by tt cfg dump with the intended location. Trace the templates-path handling from configuration loading through template lookup; done means a path such as ~/git/repo/templates/tt resolves correctly and tt create finds template tdg.