Set has_fields to false if the source type is truemoney_jumpapp. (#445)

Co-authored-by: Aashish <aashish@omise.co>

includes/gateway/class-omise-payment-truemoney.php

@@ -122,6 +122,7 @@ public function get_source()
 		$capabilities = Omise_Capabilities::retrieve();
 
 		if (!$capabilities) {
+			$this->has_fields = false;
 			return self::JUMPAPP;
 		}
 
@@ -136,6 +137,7 @@ public function get_source()
 		// Case 1: Both jumpapp and wallet are enabled
 		// Case 2: jumpapp is enabled and wallet is disabled
 		// Case 3: Both are disabled.
+		$this->has_fields = false;
 		return self::JUMPAPP;
 	}
 }