package/nmap: fix wording for nc symlink

Signed-off-by: Michael Nosthoff <buildroot@heine.tech>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit 85646943ec6fb8eeee760b89b5d31a09da7ea92b)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/nmap/Config.in

@@ -24,7 +24,7 @@ config BR2_PACKAGE_NMAP_NCAT
 	  written for the Nmap Project as a much-improved
 	  reimplementation of the venerable Netcat.
 
-	  If symlink to "nc" is installed if neither netcat or
+	  A symlink to "nc" is installed if neither netcat or
 	  netcat-openbsd is selected.
 
 comment "a symlink from ncat to 'nc' will be installed"