Fix initial inlet profile writing for MPI

[bigfooted]

Proposed Changes

Give a brief overview of your contribution here in a few sentences.
when using an inlet profile, and the inlet profile does not exist, SU2 will write a profile for you. When you do this when using mpi, this sometimes fails, depending on the number of ranks. This PR fixes the issue

Related Work

Resolve any issues (bug fix or feature request), note any related PRs, or mention interactions with the work of others, if any.
#1767

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