Use Apend(char) instead of Apend(string) for performance

When calling StringBuilder.Append with a unit length string, consider using a const char rather than a unit length const string to improve performance.

.editorconfig

@@ -194,7 +194,6 @@ dotnet_diagnostic.CA1819.severity = suggestion
 dotnet_diagnostic.CA1822.severity = suggestion
 dotnet_diagnostic.CA1823.severity = suggestion
 dotnet_diagnostic.CA1824.severity = suggestion
-dotnet_diagnostic.CA1834.severity = suggestion
 dotnet_diagnostic.CA1839.severity = suggestion
 dotnet_diagnostic.CA1840.severity = suggestion
 dotnet_diagnostic.CA1845.severity = suggestion

src/NzbDrone.Common/Http/HttpUri.cs

@@ -27,7 +27,7 @@ namespace NzbDrone.Common.Http
             if (scheme.IsNotNullOrWhiteSpace())
             {
                 builder.Append(scheme);
-                builder.Append(":");
+                builder.Append(':');
             }
 
             if (host.IsNotNullOrWhiteSpace())
@@ -36,7 +36,7 @@ namespace NzbDrone.Common.Http
                 builder.Append(host);
                 if (port.HasValue)
                 {
-                    builder.Append(":");
+                    builder.Append(':');
                     builder.Append(port);
                 }
             }
@@ -202,11 +202,11 @@ namespace NzbDrone.Common.Http
             {
                 if (builder.Length != 0)
                 {
-                    builder.Append("&");
+                    builder.Append('&');
                 }
 
                 builder.Append(Uri.EscapeDataString(pair.Key));
-                builder.Append("=");
+                builder.Append('=');
                 builder.Append(Uri.EscapeDataString(pair.Value));
             }
 

src/NzbDrone.Core/Extras/Subtitles/SubtitleService.cs

@@ -234,19 +234,19 @@ namespace NzbDrone.Core.Extras.Subtitles
 
             if (multipleCopies)
             {
-                suffixBuilder.Append(".");
+                suffixBuilder.Append('.');
                 suffixBuilder.Append(copy);
             }
 
             if (language != Language.Unknown)
             {
-                suffixBuilder.Append(".");
+                suffixBuilder.Append('.');
                 suffixBuilder.Append(IsoLanguages.Get(language).TwoLetterCode);
             }
 
             if (languageTags.Any())
             {
-                suffixBuilder.Append(".");
+                suffixBuilder.Append('.');
                 suffixBuilder.Append(string.Join(".", languageTags));
             }