remove extra space (#3152)

Author: mairaw

xml/System.Text.Json/Utf8JsonWriter.xml

@@ -59,7 +59,7 @@ To be able to format the output with indentation and white space OR to skip vali
         <summary>Constructs a new <see cref="T:System.Text.Json.Utf8JsonWriter" /> instance with a specified <see langword="System.Buffers.IBufferWriter&lt;System.Byte&gt;" />.</summary>
         <remarks>To be added.</remarks>
         <exception cref="T:System.ArgumentNullException">
-          <paramref name="bufferWriter" />  is <see langword="null" />.</exception>
+          <paramref name="bufferWriter" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName=".ctor">