VMS build: colon after target must be separated with a space

... otherwise, it's taken to be part of a device name.
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7602)

(cherry picked from commit e9994901f835420764d020968d4588fc09ec74c3)

Configurations/descrip.mms.tmpl

@@ -565,7 +565,7 @@ install_engines : check_INSTALLTOP install_runtime_libs build_engines
                 @{$unified_info{install}->{engines}}) -}
         @ {- output_on() unless scalar @{$unified_info{engines}}; "" -} !
 
-install_runtime: install_programs
+install_runtime : install_programs
 
 install_runtime_libs : check_INSTALLTOP build_libs
         @ {- output_off() if $disabled{shared}; "" -} !