Fix fret ruler extension parsing scales

extensions/fablabchemnitz/fret_ruler/scales/cet63g.scl

@@ -0,0 +1,54 @@
+! cet63g.scl
+!
+49th root of 6
+ 49
+!
+ 63.30520
+ 126.61041
+ 189.91561
+ 253.22082
+ 316.52602
+ 379.83122
+ 443.13643
+ 506.44163
+ 569.74684
+ 633.05204
+ 696.35725
+ 759.66245
+ 822.96765
+ 886.27286
+ 949.57806
+ 1012.88327
+ 1076.18847
+ 1139.49367
+ 1202.79888
+ 1266.10408
+ 1329.40929
+ 1392.71449
+ 1456.01969
+ 1519.32490
+ 1582.63010
+ 1645.93531
+ 1709.24051
+ 1772.54571
+ 1835.85092
+ 1899.15612
+ 1962.46133
+ 2025.76653
+ 2089.07174
+ 2152.37694
+ 2215.68214
+ 2278.98735
+ 2342.29255
+ 2405.59776
+ 2468.90296
+ 2532.20816
+ 2595.51337
+ 2658.81857
+ 2722.12378
+ 2785.42898
+ 2848.73418
+ 2912.03939
+ 2975.34459
+ 3038.64980
+ 6/1