Fix retroarch cores in es_find_rules.xml (#1460)

Author: matakko

configs/emulationstation/custom_systems/es_find_rules.xml

@@ -15,7 +15,7 @@
     </emulator>
     <core name="RETROARCH">
         <rule type="corepath">
-            <entry>~/.config/retroarch/cores</entry>
+            <entry>~/.var/app/org.libretro.RetroArch/config/retroarch/cores</entry>
         </rule>
     </core>
     <emulator name="SHADPS4">
@@ -128,4 +128,4 @@
             <entry>/run/media/mmcblk0p1/Emulation/tools/launchers/xenia.sh</entry>
         </rule>
     </emulator>
-</ruleList>
+</ruleList>