Update Citra Android download link.

Changes the download link from the citra-emu.org downloads page to the Nightly repo, as that is more updated than the current Play Store version.

src/responses/citra.json

@@ -5,7 +5,7 @@
       "requirements": { "reply": "Please refer to our **Frequently Asked Questions**. The only requirements for Citra are a GPU that supports at least OpenGL 4.3 and a 64-bit OS, but you definitely want a processor with the highest possible performance per core. <https://citra-emu.org/wiki/faq/>"},
       "roms": { "reply": "Please read our __community rules__. Warez/downloading games talk is strictly prohibited. To prevent legal issues, you are not allowed to post links or refer to any kind of ROM, NAND, ISO, game, or other copyrighted material that has been illegally obtained or shared. <https://citra-emu.org/rules/>"},
       "dump-game": { "reply": "Please refer to our __game dumping guides__. \nFor Cartridges: <https://citra-emu.org/wiki/dumping-game-cartridges/> \nFor Installed Titles: <https://citra-emu.org/wiki/dumping-installed-titles/> \nTo dump DLC and Updates, use this guide <https://citra-emu.org/wiki/dumping-updates-and-dlcs/> and install the results through `File -> Install CIA...`"},
-      "apk": { "reply": "Official Citra for Android has been released! Download the .apk from <https://citra-emu.org/download/>. \nPlease note that the current app is a beta version and not everything works right away. We will continue to fix issues/bugs and release updates."},
+      "apk": { "reply": "Official Citra for Android has been released! Download the .apk from <https://github.com/citra-emu/citra-nightly/releases>. \nIf you have the Citra Android app from the Google Play Store installed, please uninstall it before installing from our Nightly repo. Your save data will transfer over and if you have paid for Citra Premium, that will transfer over too. \n\nPlease note that the current app is a beta version and not everything works right away. We will continue to fix issues/bugs and release updates."},
       "dump-system": { "reply": "Please refer to our __system dumping guide__: <https://citra-emu.org/wiki/dumping-system-archives-and-the-shared-fonts-from-a-3ds-console/>"},
       "compat": { "reply": "Click here to view our game compatibility list: <https://citra-emu.org/game/>. ***A Reminder***: Compatibility ratings are user submitted data and may not accurately reflect the game's playability. Your experience may or may not be the same due to differences in hardware or software environments."},
       "updates": { "reply": "You can check our latest updates on *Github*. <https://github.com/citra-emu/citra/pulse>"},