do not show an empty list

openpkg/rpmpopt

@@ -22,7 +22,7 @@ Vendor:  %-27{VENDOR} Install Size: %{SIZE} bytes\n\
 URL:     %-27{URL} Install Time: %|INSTALLTIME?{%{INSTALLTIME:date}}:{(not installed)}|\n\
 Summary: %{SUMMARY}\n\
 Description:\n%{DESCRIPTION}\n\
-Provides:\n\
-[    %{PROVIDENAME} %|PROVIDEFLAGS?{%{PROVIDEFLAGS:depflags} %{PROVIDEVERSION}}:{}|\n]\
+%|PROVIDENAME?{Provides:\n\
+[    %{PROVIDENAME} %|PROVIDEFLAGS?{%{PROVIDEFLAGS:depflags} %{PROVIDEVERSION}}:{}|\n]}:{}|\
 '