Fixed czech translation of 'Light Theme' (#1160)

Author: zdenekobornik

app/src/main/res/values-cs/strings.xml

@@ -155,7 +155,7 @@
     <string name="settingsHeadingGeneral">Obecné</string>
     <string name="settingsHeadingOther">Jiné</string>
     <string name="settingsHeadingPrivacy">Soukromí</string>
-    <string name="settingsLightTheme">Lehký motiv</string>
+    <string name="settingsLightTheme">Světlý motiv</string>
     <string name="settingsAboutDuckduckgo">O DuckDuckGo</string>
     <string name="settingsVersion">Verze</string>
     <string name="leaveFeedback">Podělte se o zpětnou vazbu</string>