imapd dislikes parallel building under Solaris

imapd/imapd.spec

@@ -76,7 +76,7 @@ AutoReqProv:  no
         --with-cyrus-prefix=%{l_prefix} \
         --with-cyrus-user=%{l_fsusr} \
         --with-cyrus-group=%{l_fsgrp}
-    %{l_make} %{l_mflags -O}
+    %{l_make} %{l_mflags}
 
 %install
     rm -rf $RPM_BUILD_ROOT