Fix the option used for ClustalOmega, when one wants to specify the

sequence type.  The previously used --t would be interpreted by
clustalo as a shortcut for --threads, resulting in error.

Bio/Align/Applications/_ClustalOmega.py

@@ -63,7 +63,7 @@ def __init__(self, cmd="clustalo", **kwargs):
                     "Pre-aligned multiple sequence file (aligned columns will be kept fix).",
                     filename=True,
                     equate=False),
-            _Option(["--t", "--seqtype", "seqtype"],
+            _Option(["-t", "--seqtype", "seqtype"],
                     "{Protein, RNA, DNA} Force a sequence type (default: auto).",
                     equate=False,
                     checker_function=lambda x: x in ["protein", "rna", "dna",