Re-added effective_srate fix from 1.11 that was missing in 1.12

Author: cboulay

Matlab/xdf/load_xdf.m

@@ -503,7 +503,7 @@
                 segments(r).t_begin = temp(k).time_stamps(range(1));
                 segments(r).t_end = temp(k).time_stamps(range(2));
                 segments(r).duration = segments(r).t_end - segments(r).t_begin;
-                segments(r).effective_srate = segments(r).num_samples / segments(r).duration;
+                segments(r).effective_srate = (segments(r).num_samples-1)/ segments(r).duration;
             end
 
             % calculate the weighted mean sampling rate over all segments