patch 8.2.2143: Vim9: dead code in compiling :unlet

Problem:    Vim9: dead code in compiling :unlet.
Solution:   Don't check for "!" a second time.
diff --git a/src/version.c b/src/version.c
index be7e4f0..be8c64a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2143,
+/**/
     2142,
 /**/
     2141,
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 3fae25e..86d3260 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -5993,7 +5993,7 @@
     // for "[var, var] = expr" drop the "expr" value
     if (var_count > 0 && !semicolon)
     {
-	    if (generate_instr_drop(cctx, ISN_DROP, 1) == NULL)
+	if (generate_instr_drop(cctx, ISN_DROP, 1) == NULL)
 	    goto theend;
     }
 
@@ -6074,12 +6074,6 @@
 	return NULL;
     }
 
-    if (*p == '!')
-    {
-	p = skipwhite(p + 1);
-	eap->forceit = TRUE;
-    }
-
     ex_unletlock(eap, p, 0, GLV_NO_AUTOLOAD, compile_unlet, cctx);
     return eap->nextcmd == NULL ? (char_u *)"" : eap->nextcmd;
 }