Update books/04_Numbers.tex

Various typos changed:

Num 3:4 -- "priest" changed to "priests".

Num 4:16 -- change in serial list

Num 4:35 -- redundant "fifty" removed.

Num 5:10 -- redundant "and" and "regarding" removed.

Amended by Charles Welty. Authorized by William P. Welty, Ph.D. of The ISV Foundation on 06 JAN 2013 at 9:13AM PST.