Corrected bug in BDIO_seek!

Thanks to Fabian Joswig <fabian.joswig@wwu.de>

When calling BDIO_seek the very last record of a bdio file cannot be
accessed due to ipt < length(fb.records)) and ipt starting at 1. If I
understand it correctly you would have to change the condition to ipt
<= length(fb.records)) in order to be able to access the last
record. I noticed this because I did not attach an additional record
containing the hash and then BDIO_seek immediately returns false.

src/BDIOmethods.jl

@@ -267,7 +267,7 @@ function BDIO_seek!(fb::BDIOstream, icnt::Int = 1)
     else
         ipt += icnt
     end
-    if (ipt < length(fb.records))&&(ipt > 0)
+    if (ipt <= length(fb.records))&&(ipt > 0)
         fb.ipt = ipt
         fb.rwpos = 0
         return true