Description of problem:
pdfmod is not working unless you have gnome-sharp installed

❱ pdfmod 
[1 Debug 09:54:32.118] Starting PdfMod 0.9.1
[1 Debug 09:54:32.136] Initializing i18n catalog from /usr/share/locale/

Unhandled Exception:
System.TypeLoadException: Could not load type of field 'PdfMod.Core.Configuration:client' (0) due to: Could not load file or assembly 'gconf-sharp, Version=2.24.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f' or one of its dependencies.
  at PdfMod.PdfMod.Main (System.String[] args) [0x0004d] in <0cab43656a5b4e3895301a82b0acd3a0>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeLoadException: Could not load type of field 'PdfMod.Core.Configuration:client' (0) due to: Could not load file or assembly 'gconf-sharp, Version=2.24.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f' or one of its dependencies.
  at PdfMod.PdfMod.Main (System.String[] args) [0x0004d] in <0cab43656a5b4e3895301a82b0acd3a0>:0


Version-Release number of selected component (if applicable):
pdfmod-0.9.1-21.fc31.x86_64


How reproducible:
install pdfmod on system where gnome-sharp is not installed and run it.

Steps to Reproduce:
1.install pdfmod on system where gnome-sharp is not installed and run it.
2.try to run pdfmod


Actual results:
Unhandled Exception:
System.TypeLoadException: Could not load type of field 'PdfMod.Core.Configuration:client' (0) due to: Could not load file or assembly 'gconf-sharp, Version=2.24.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f' or one of its dependencies.
  at PdfMod.PdfMod.Main (System.String[] args) [0x0004d] in <0cab43656a5b4e3895301a82b0acd3a0>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeLoadException: Could not load type of field 'PdfMod.Core.Configuration:client' (0) due to: Could not load file or assembly 'gconf-sharp, Version=2.24.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f' or one of its dependencies.
  at PdfMod.PdfMod.Main (System.String[] args) [0x0004d] in <0cab43656a5b4e3895301a82b0acd3a0>:0


Expected results:
pdfmod runs, all dependencies are defined the package manifest

Additional info:
Fix:
sudo dnf install gnome-sharp
pdfmod 
[1 Debug 09:58:52.651] Starting PdfMod 0.9.1
[1 Debug 09:58:52.670] Initializing i18n catalog from /usr/share/locale/
[1 Debug 09:58:52.713] Cache directory set to /home/brq/mzink/.cache/pdfmod
...Works now.