json-for-modern-cpp: fix license hash

Fixes:

  http://autobuild.buildroot.net/results/942485b94f21567c2f35a1a3cc62450f3461a4f9

Signed-off-by: Adam Duskett <aduskett@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/json-for-modern-cpp/json-for-modern-cpp.hash

@@ -1,3 +1,3 @@
 # Locally computed
 sha256	b20be343922f73504baf8a01543c2a42d16e01f18bb231b324a8959416ccf4f8	json-v3.1.0.tar.gz
-sha256	6a6115fc4a7239a135f2dce8d33f94cb8a936b8f608ac0f6699fbac278b0dd5b	LICENSE.MIT
+sha256	7b875bb7a4e28abb7956ea821b4b7d88ff6a2a4fabf261c3993730a365ec56dd	LICENSE.MIT