Solution
On my Fedora 30, I installed the following packages manually:
iniparser-4.1 python3-aiodns-1.1.1 python3-aiohttp-3.5.4 python3-aiohttp-cors-0.7.0 python3-async-timeout-3.0.0 python3-babel-2.6.0 python3-jinja2-2.10.1 python3-multidict-4.3.1 python3-prompt-toolkit-2.0.9 python3-pycares-2.3.0 python3-pygments-2.2.0 python3-wcwidth-0.1.7 python3-yarl-1.3.0 python3-zipstream-1.1.4 ubridge-0.9.14
And Next, I used the command below to install gns3-server:
$ sudo pip3 install gns3-server==2.1.11
And Next: $ sudo dnf install gns3