Add newline at end of KRHangulMapping.h

without this, GCC 11 -E -fdirectives-only produces this:

extern const uint16_t ksc5601_hangul_to_unicode[2350];# 38 "/workdir/UnpackedTarball/zxing/core/src/textcodec/KRHangulMapping.cpp" 2

and compiling that fails with:

KRHangulMapping.h:38:55: error: stray '#' in program

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100392

--- zxing/core/src/textcodec/KRHangulMapping.h.orig	2021-05-01 18:00:09.011795242 +0200
+++ zxing/core/src/textcodec/KRHangulMapping.h	2021-05-01 18:00:16.774788294 +0200
@@ -35,4 +35,4 @@
 #include <cstdint>
 
 /* Table including ksc5601 hangul to unicode */
-extern const uint16_t ksc5601_hangul_to_unicode[2350];
\ No newline at end of file
+extern const uint16_t ksc5601_hangul_to_unicode[2350];