Revert "eos and UNK will be overwritten if they occur in the corpus, should always be 0 and 1"
Revert "eos and UNK will be overwritten if they occur in the corpus, should always be 0 and 1"

Actually fine if there are weird values, as Nematus does not really use them.

This reverts commit 09eb3594fb395d43dd3f6c2a4dec85af683cbb30.

EdinburghNLP/nematus,yang1fan2/nematus,yang1fan2/nematus,yang1fan2/nematus,Proyag/nematus,Proyag/nematus,yang1fan2/nematus,cshanbo/nematus,yang1fan2/nematus,yang1fan2/nematus,shuoyangd/nematus,EdinburghNLP/nematus,shuoyangd/nematus,EdinburghNLP/nematus,rsennrich/nematus,yang1fan2/nematus,yang1fan2/nematus,rsennrich/nematus,EdinburghNLP/nematus,rsennrich/nematus,rsennrich/nematus,rsennrich/nematus,yang1fan2/nematus,Proyag/nematus,cshanbo/nematus,shuoyangd/nematus,shuoyangd/nematus,Proyag/nematus,rsennrich/nematus,EdinburghNLP/nematus,cshanbo/nematus,Proyag/nematus,cshanbo/nematus,shuoyangd/nematus,Proyag/nematus,cshanbo/nematus,shuoyangd/nematus,yang1fan2/nematus,cshanbo/nematus,EdinburghNLP/nematus