dev-python/networkx: fix sphinx error

Bug: https://bugs.gentoo.org/594626
Package-Manager: Portage-2.3.6_p1, Repoman-2.3.2_p69

dev-python/networkx/files/1.11-sphinx-pngmath.patch

@@ -0,0 +1,14 @@
+Drop pngmath extenstion from sphinx config
+
+Bug: https://bugs.gentoo.org/594626
+
+--- a/doc/source/conf.py
++++ b/doc/source/conf.py
+@@ -74,7 +74,6 @@ def cd(newpath):
+     'sphinx.ext.intersphinx',
+     'sphinx.ext.mathjax',
+     'sphinx.ext.napoleon',
+-    'sphinx.ext.pngmath',
+     'sphinx.ext.todo',
+     'sphinx.ext.viewcode',
+     #'sphinxcontrib.bibtex',

dev-python/networkx/networkx-1.11.ebuild

@@ -43,6 +43,10 @@ RDEPEND="
 		dev-python/pyyaml[${PYTHON_USEDEP}]
 	)"
 
+PATCHES=(
+	"${FILESDIR}"/1.11-sphinx-pngmath.patch
+)
+
 pkg_setup() {
 	use doc && DISTUTILS_ALL_SUBPHASE_IMPLS=( 'python2*' )
 }
@@ -54,13 +58,7 @@ python_prepare_all() {
 }
 
 python_compile_all() {
-	# https://github.com/networkx/networkx/issues/1263
-	if use doc; then
-		sed \
-			-e "s:^\t\./:\t${PYTHON} :g" \
-			-i doc/Makefile || die
-		emake -C doc html
-	fi
+	use doc && emake -C doc html
 }
 
 python_test() {