Need to target 4.6 for mono to compile it

Author: shana

src/OctoRun/OctoRun.csproj

@@ -9,7 +9,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>OctoRun</RootNamespace>
     <AssemblyName>octorun</AssemblyName>
-    <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <BuildType Condition="Exists('$(SolutionDir)\script\src\ApplicationInfo_Local.cs')">Internal</BuildType>