patch 8.1.1724: too much overhead checking for CTRL-C while processing text

Problem:    Too much overhead checking for CTRL-C while processing text.
Solution:   Increase BREAKCHECK_SKIP.  Remove the difference for when built
            with the GUI. (suggested by Andy Massimino, closes #4708)
diff --git a/src/feature.h b/src/feature.h
index 37af4c0..74ea8d5 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -483,6 +483,11 @@
 # define FEAT_TEXT_PROP
 #endif
 
+#if defined(FEAT_SYN_HL) && defined(FEAT_RELTIME)
+// Can limit syntax highlight time to 'redrawtime'.
+# define SYN_TIME_LIMIT 1
+#endif
+
 /*
  * +spell		spell checking
  *
diff --git a/src/misc1.c b/src/misc1.c
index f5549fd..7df3954 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -3182,11 +3182,7 @@
  */
 
 #ifndef BREAKCHECK_SKIP
-# ifdef FEAT_GUI		    /* assume the GUI only runs on fast computers */
-#  define BREAKCHECK_SKIP 200
-# else
-#  define BREAKCHECK_SKIP 32
-# endif
+# define BREAKCHECK_SKIP 1000
 #endif
 
 static int	breakcheck_count = 0;
diff --git a/src/screen.c b/src/screen.c
index 7998710..bd76f7b 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -167,11 +167,6 @@
 /* Ugly global: overrule attribute used by screen_char() */
 static int screen_char_attr = 0;
 
-#if defined(FEAT_SYN_HL) && defined(FEAT_RELTIME)
-/* Can limit syntax highlight time to 'redrawtime'. */
-# define SYN_TIME_LIMIT 1
-#endif
-
 #ifdef FEAT_RIGHTLEFT
 # define HAS_RIGHTLEFT(x) x
 #else
diff --git a/src/version.c b/src/version.c
index 5dc4d0c..8a98f51 100644
--- a/src/version.c
+++ b/src/version.c
@@ -778,6 +778,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1724,
+/**/
     1723,
 /**/
     1722,