Fix a crash when MAX_WORD_LENGTH is too short.

Change-Id: Idcb5aa2685321b8d0ac7d846caecbd1c79e4dd77
diff --git a/native/src/bigram_dictionary.cpp b/native/src/bigram_dictionary.cpp
index 095b805..7bfef38 100644
--- a/native/src/bigram_dictionary.cpp
+++ b/native/src/bigram_dictionary.cpp
@@ -146,7 +146,7 @@
         bool firstAddress = true;
         bool haveToSearchAll = true;
 
-        if (depth >= 0) {
+        if (depth < MAX_WORD_LENGTH && depth >= 0) {
             word[depth] = (unsigned short) followingChar;
         }
         pos = followDownBranchAddress; // pos start at count