lnrpc+rpcserver: expose git commit hash in getinfo

lnrpc/rpc.proto

@@ -1660,6 +1660,9 @@ message GetInfoResponse {
     /// The version of the LND software that the node is running.
     string version = 14;
 
+    /// The SHA1 commit hash that the daemon is compiled with.
+    string commit_hash = 20;
+
     /// The identity pubkey of the current node.
     string identity_pubkey = 1;
 

lnrpc/rpc.swagger.json

@@ -2923,6 +2923,10 @@
           "type": "string",
           "description": "/ The version of the LND software that the node is running."
         },
+        "commit_hash": {
+          "type": "string",
+          "description": "/ The SHA1 commit hash that the daemon is compiled with."
+        },
         "identity_pubkey": {
           "type": "string",
           "description": "/ The identity pubkey of the current node."

rpcserver.go

@@ -2408,6 +2408,7 @@ func (r *rpcServer) GetInfo(ctx context.Context,
 		Color:               routing.EncodeHexColor(nodeAnn.RGBColor),
 		BestHeaderTimestamp: int64(bestHeaderTimestamp),
 		Version:             build.Version() + " commit=" + build.Commit,
+		CommitHash:          build.CommitHash,
 		SyncedToGraph:       isGraphSynced,
 		Features:            features,
 	}, nil