add libstdc++

Dockerfile

@@ -6,6 +6,7 @@ RUN apk --no-cache add \
     git \
     gcc \
     olm-dev \
+    libstdc++ \
     musl-dev
 
 WORKDIR /build
@@ -24,7 +25,8 @@ RUN adduser -h /var/lib/matrix-bridge -u 2222 -D -G matrix-bridge matrix-bridge
 COPY --from=builder /build/bin/mautrix-whatsapp /bin/mautrix-whatsapp
 
 RUN apk --no-cache add \
-    ca-certificates
+    ca-certificates \
+    libstdc++
 
 RUN apk --no-cache --repository=http://dl-cdn.alpinelinux.org/alpine/edge/main add \
     olm