disable PyQwt support on f26++

PyQwt currently FTBFS and has broken deps

qgis.spec

@@ -69,7 +69,7 @@ BuildRequires:  postgresql-devel
 BuildRequires:  proj-devel
 BuildRequires:  PyQt4-devel
 # PyQwt doesn't support qwt6, so just turn it off for now on RHEL
-%if 0%{?fedora}
+%if 0%{?fedora} < 26
 BuildRequires:  PyQwt-devel
 %endif
 BuildRequires:  python2-devel
@@ -406,7 +406,7 @@ update-mime-database %{?fedora:-n} %{_datadir}/mime &> /dev/null || :
 
 %changelog
 * Sun Jan 01 2017 Rex Dieter <rdieter@math.unl.edu> - 2.18.2-2
-- rebuild (sip)
+- rebuild (sip), disable PyQwt support (f26+, for now)
 
 * Fri Dec 16 2016 Volker Froehlich <volker27@gmx.at> - 2.18.2-1
 - New upstream release