Apply suggestions from @davidlehn code review

Co-Authored-By: David I. Lehn <[email protected]>

Author: gkellogg

lib/context.js

@@ -530,8 +530,8 @@ api.createTermDefinition = ({
     if((type === '@json' || type === '@none')) {
       if(api.processingMode(activeCtx, 1.0)) {
         throw new JsonLdError(
-          'Invalid JSON-LD syntax; an @context @type value not be ' +
-          '#{type} in JSON-LD 1.0 mode.',
+          'Invalid JSON-LD syntax; an @context @type value must not be ' +
+          `"${type}" in JSON-LD 1.0 mode.`,
           'jsonld.SyntaxError',
           {code: 'invalid type mapping', context: localCtx});
       }