Fix ETH Ropsten: websocket: read limit exceeded trezor#490

Geth sets maxRequestContentLength to 5M.
However, Ropsten contains blocks of largers size (for example 599281).
These which cannot be fetched using API.

Fixed by hacky way of modifying the geth source before
the build of the project.
Will submit PR to go-ethereum with final fix.

build/docker/bin/Makefile

@@ -35,6 +35,8 @@ prepare-sources:
 	@ [ -n "`ls /src 2> /dev/null`" ] || (echo "/src doesn't exist or is empty" 1>&2 && exit 1)
 	rm -rf $(BLOCKBOOK_SRC)
 	cp -r /src $(BLOCKBOOK_SRC)
+	cd $(BLOCKBOOK_SRC) && go mod download
+	sed -i 's/maxRequestContentLength\ =\ 1024\ \*\ 1024\ \*\ 5/maxRequestContentLength = 1024 * 1024 * 20/g' $(GOPATH)/pkg/mod/github.com/ethereum/go-ethereum*/rpc/http.go
 
 generate-data:
 	cd $(BLOCKBOOK_SRC) && packr clean && packr