fix dependencies

Author: justcoding121

src/Titanium.Web.Proxy/Titanium.Web.Proxy.nuspec

@@ -14,10 +14,15 @@
     <copyright>Copyright &#x00A9; Titanium.  All rights reserved.</copyright>
     <tags></tags>
     <dependencies>
-	  <dependency id="StreamExtended" version="1.0.179" />
-	  <dependency id="Portable.BouncyCastle" version="1.8.2" />
-	  <dependency id="BrotliSharpLib" version="0.3.1" />
+	  <group targetFramework="net45">
+		  <dependency id="StreamExtended" version="1.0.179" />
+		  <dependency id="Portable.BouncyCastle" version="1.8.2" />
+		  <dependency id="BrotliSharpLib" version="0.3.1" />
+	  </group>
 	  <group targetFramework="netstandard2.0">
+		  <dependency id="StreamExtended" version="1.0.179" />
+		  <dependency id="Portable.BouncyCastle" version="1.8.2" />
+		  <dependency id="BrotliSharpLib" version="0.3.1" />
 		  <dependency id="Microsoft.Win32.Registry" version="4.4.0" />
 		  <dependency id="System.Security.Principal.Windows" version="4.4.1" />
 	  </group>