patch 7.4.1501

Problem:    Garbage collection with an option channel is not tested.
Solution:   Call garbagecollect() in the test.

src/testdir/test_channel.vim

@@ -146,6 +146,9 @@ func s:communicate(port)
   endif
   call assert_equal('got it', s:responseMsg)
 
+  " Collect garbage, tests that our handle isn't collected.
+  call garbagecollect()
+
   " check setting options (without testing the effect)
   call ch_setoptions(handle, {'callback': 's:NotUsed'})
   call ch_setoptions(handle, {'timeout': 1111})

src/version.c

@@ -743,6 +743,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1501,
 /**/
     1500,
 /**/