Fix a crash in the dictionary due to releasing a null array.

dictionary/jni/com_android_inputmethod_latin_BinaryDictionary.cpp

@@ -107,7 +107,9 @@ static int latinime_BinaryDictionary_getSuggestions(
     env->ReleaseIntArrayElements(frequencyArray, frequencies, 0);
     env->ReleaseIntArrayElements(inputArray, inputCodes, JNI_ABORT);
     env->ReleaseCharArrayElements(outputArray, outputChars, 0);
+    if (nextLetters) {
         env->ReleaseIntArrayElements(nextLettersArray, nextLetters, 0);
+    }
 
     return count;
 }