Return empty if cna't be locked

main.py

@@ -84,7 +84,7 @@ async def fastapi_import_inp(network: str, req: Request):
     return import_inp(network, ChangeSet(ps))
 
 @app.get("/exportinp/")
-async def fastapi_export_inp(network: str):
+async def fastapi_export_inp(network: str) -> ChangeSet:
     return export_inp(network)
 
 @app.post("/readinp/")
@@ -126,7 +126,8 @@ async def fastapi_lock_project(network: str, req: Request):
     client_host = req.client.host
     if fastapi_is_locked(network, req) == False:
         lockedPrjs[network] = client_host
-    return client_host
+        return client_host
+    return ""
 
 @app.post("/unlockproject/")
 async def fastapi_unlock_project(network: str, req: Request):