add error message to bestbestfit.py when file does not have 2 lines

work/tools/python/bestbestfit.py

@@ -13,6 +13,10 @@ for dir in sys.argv[1:]:
     chi2min=sys.float_info.max
     data=np.zeros(1)
     for bf in bestfits:
+        nlines=len(open(bf).readlines())
+        if nlines != 2:
+            print("invalid bestfit file:{} (skipping)".format(bf))
+            continue
         if not header:
             with open(bf,'r') as f:
                 line = f.readline().rstrip()