fix: remove boxShadow for web (#267)

Author: Maskedman99

src/views/Header/HeaderBackground.tsx

@@ -24,9 +24,8 @@ const styles = StyleSheet.create({
         },
       },
       default: {
-        // https://github.com/necolas/react-native-web/issues/44
-        // Material Design
-        boxShadow: `0 2px 4px -1px rgba(0,0,0,0.2), 0 4px 5px 0 rgba(0,0,0,0.14), 0 1px 10px 0 rgba(0,0,0,0.12)`,
+        borderBottomWidth: StyleSheet.hairlineWidth,
+        borderBottomColor: 'rgba(156, 156, 156, 0.50)',
       },
     }),
   },