Fixed RPM build script.

scripts/rpm-data/klayout.spec

@@ -31,6 +31,8 @@ Source0:        http://www.klayout.de/downloads/%{name}-%{version}.tar.gz
 # so's of klayout itself)
 AutoReqProv: 	no
 
+%define buildopt -j2
+
 # CentOS7 requirements
 %if "%{target_system}" == "centos7"
 Requires:	ruby >= 2.0.0
@@ -43,7 +45,8 @@ Requires: qt-x11 >= 4.8.5
 Requires: libcurl >= 7.19.7
 Requires: ruby >= 1.8.7
 Requires: python >= 2.6.6
-%define buildopt -libcurl
+Requires: qt-x11 >= 4.6.2
+%define buildopt -libcurl %{buildopt}
 %endif
 
 %if "%{target_system}" == "opensuse42_2"
@@ -89,8 +92,7 @@ cd %{_sourcedir}
 ./build.sh -rpath %{_libdir}/klayout \
            -bin %{_builddir}/bin.$TARGET \
            -build %{_builddir}/build.$TARGET \
-           %{buildopt} \
-           -j2 
+           %{buildopt} 
 
 cp -p LICENSE Changelog CONTRIB %{_builddir}
 strip %{_builddir}/bin.$TARGET/*