Docs: Fix rpm dependencies example (#16272)

The current version of Grafana requires the package ```urw-fonts```.

docs/sources/installation/rpm.md

@@ -50,7 +50,7 @@ $ wget https://dl.grafana.com/oss/release/grafana-5.4.2-1.x86_64.rpm
 ### On CentOS / Fedora / Redhat:
 
 ```bash
-$ sudo yum install initscripts fontconfig
+$ sudo yum install initscripts urw-fonts
 $ sudo rpm -Uvh <local rpm package>
 ```
 
@@ -206,4 +206,4 @@ binary and the `public` folder is located).
 ## Logging in for the first time
 
 To run Grafana open your browser and go to http://localhost:3000/. 3000 is the default http port that Grafana listens to if you haven't [configured a different port](/installation/configuration/#http-port).
-Then follow the instructions [here](/guides/getting_started/).
\ No newline at end of file
+Then follow the instructions [here](/guides/getting_started/).