Update copyright year

Author: yvt

res/mkmacosbundle/Info.plist

@@ -27,7 +27,7 @@
     <key>LSMinimumSystemVersion</key>
     <string>10.12</string>
     <key>NSHumanReadableCopyright</key>
-    <string>Copyright © 2019 yvt. All rights reserved.</string>
+    <string>Copyright © 2020 yvt. All rights reserved.</string>
     <key>NSMainNibFile</key>
     <string>MainMenu</string>
     <key>NSPrincipalClass</key>

res/windres/stella2.rc

@@ -42,7 +42,7 @@ BEGIN
             VALUE "FileDescription", "Stella2 application"
             VALUE "FileVersion", "1.0.0.1"
             VALUE "InternalName", "Stella2"
-            VALUE "LegalCopyright", "Copyright (C) 2019"
+            VALUE "LegalCopyright", "Copyright (C) 2020"
             VALUE "OriginalFilename", "Stella2"
             VALUE "ProductName", "Stella2"
             VALUE "ProductVersion", "1.0.0.1"