docs($q): fix typo in qFactory documentation

Closes angular#15946

Author: dtarasiuk

src/ng/q.js

@@ -280,7 +280,7 @@ function $$QProvider() {
  * @param {function(function)} nextTick Function for executing functions in the next turn.
  * @param {function(...*)} exceptionHandler Function into which unexpected exceptions are passed for
  *     debugging purposes.
- @ param {=boolean} errorOnUnhandledRejections Whether an error should be generated on unhandled
+ * @param {boolean=} errorOnUnhandledRejections Whether an error should be generated on unhandled
  *     promises rejections.
  * @returns {object} Promise manager.
  */