Update nextflow.config

Correction from @muffato

Co-authored-by: Matthieu Muffato <mm49@sanger.ac.uk>

Author: DLBPointon

nextflow.config

@@ -265,7 +265,7 @@ manifest {
     homePage        = 'https://github.com/sanger-tol/curationpretext'
     description     = """A simple pipeline to generate pretext files for genomic curation."""
     mainScript      = 'main.nf'
-    defaultBranch   = 'master'
+    defaultBranch   = 'main'
     nextflowVersion = '!>=24.10.5'
     version         = '1.5.0'
     doi             = '10.5281/zenodo.12773958'