external: Update jnipp

src/external/jnipp/jnipp.cpp

@@ -1480,6 +1480,10 @@ namespace jni
             ((jvalue*) v)->l = env()->NewStringUTF(a);
         }
 
+        void valueArg(value_t* v, std::nullptr_t)
+        {
+            ((jvalue*) v)->l = nullptr;
+        }
 
         template <> void cleanupArg<const char*>(value_t* v)
         {

src/external/jnipp/jnipp.h

@@ -134,6 +134,7 @@ namespace jni
         void valueArg(value_t* v, const char* a);
         void valueArg(value_t* v, const std::wstring& a);
         void valueArg(value_t* v, const wchar_t* a);
+        void valueArg(value_t* v, std::nullptr_t);
 
         inline void args(value_t*) {}