Fix lingering reference to LAS 1.4 (#131)

Author: esilvia

source/02.04_header.sub

@@ -384,8 +384,8 @@ point records in the file, these values must be set to zero.
 This value provides the offset, in bytes, from the beginning of the LAS file to
 the first byte of the Waveform Data Package Record. Note that this will be the
 first byte of the Waveform Data Packet header. If no waveform records are
-contained within the file or they are stored externally, this value must be zero. It should be noted that LAS
-1.4 allows multiple Extended Variable Length Records (EVLRs) and that the
+contained within the file or they are stored externally, this value must be zero. It should be noted that
+LAS 1.5 allows multiple Extended Variable Length Records (EVLRs) and that the
 Waveform Data Packet Record is not necessarily the first EVLR in the file.
 
 **Start of First Extended Variable Length Record**