updated image

src/chains/mainnet/mars.json

@@ -16,14 +16,14 @@
     "coin_type": "118",
     "sdk_version": "0.46.8",
     "addr_prefix": "mars",
-    "logo": "/logos/mars.jpg",
+    "logo": "/logos/mars.png",
     "assets": [
         {
             "base": "umars",
             "symbol": "MARS",
             "exponent": "6",
             "coingecko_id": "",
-            "logo": "/logos/mars.jpg"
+            "logo": "/logos/mars.png"
         }
     ]
 }