JNI-174 Wrap __LP64__ related stuff into ifdef ANDROID to keep JNI-158 and don't break dates on android.

On android32 bits time_t struct it is 32 bits and this is causing an overflow after 01/Feb/22 giving negative dates and therefore converting from 09/02/22 to 25/02/21.

src/cxx/jniutils.cc

@@ -1,7 +1,9 @@
-#include <cassert>
 #include "jniutils.hh"
 #include <pEp/pEpLog.hh>
+#include <cassert>
+#include <cstring>
 
+#ifdef ANDROID
     #ifndef __LP64__
 
         #include <time64.h>
@@ -9,8 +11,7 @@
         #define time_t time64_t
         #define timegm timegm64
         #define gmtime_r gmtime64_r
-#else
-#include <string.h>
+    #endif
 #endif
 
 namespace pEp {