Try to fix Appveyor build

Seems to be related to this:
java-native-access/jna#633

src/main/java/org/sqlite/SQLite.java

@@ -12,21 +12,23 @@
 import com.sun.jna.Library;
 import com.sun.jna.Memory;
 import com.sun.jna.Native;
+import com.sun.jna.NativeLibrary;
 import com.sun.jna.Pointer;
 import com.sun.jna.PointerType;
 import com.sun.jna.ptr.IntByReference;
 import com.sun.jna.ptr.PointerByReference;
 
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
+import java.util.Collections;
 
 // TODO JNA/Bridj/JNR/JNI and native libs embedded in JAR.
 public final class SQLite implements Library {
 	private static final String JNA_LIBRARY_NAME = "sqlite3";
 
 	// public static final NativeLibrary JNA_NATIVE_LIB = NativeLibrary.getInstance(SQLite.JNA_LIBRARY_NAME);
 	static {
-		Native.register(JNA_LIBRARY_NAME);
+		Native.register(NativeLibrary.getInstance(JNA_LIBRARY_NAME, Collections.singletonMap(OPTION_STRING_ENCODING, "UTF-8")));
 	}
 
 	public static final int SQLITE_OK = 0;