change gmsh urls and fix linting in docstring

docs/source/release_notes/0.4.rst

@@ -115,7 +115,7 @@ Improvements to pyMOR's discretizaion tookit
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 - An unstructured triangular |Grid| is now provided by :class:`~pymor.grids.unstructured.UnstructuredTriangleGrid`.
   Such a |Grid| can be obtained using the :meth:`~pymor.domaindiscretizers.gmsh.discretize_gmsh`
-  method, which can parse `Gmsh <http://gmsh.info/>`_ output files. Moreover, this
+  method, which can parse `Gmsh <https://gmsh.info/>`_ output files. Moreover, this
   method can generate `Gmsh` input files to create unstructured meshes for
   an arbitrary :class:`~pymor.domaindescriptions.polygonal.PolygonalDomain`
   `[#9] <https://github.com/pymor/pymor/issues/9>`_.

src/pymor/discretizers/builtin/domaindiscretizers/gmsh.py

@@ -38,7 +38,7 @@ def discretize_gmsh(domain_description=None, geo_file=None, geo_file_path=None,
         Mesh element size scaling factor.
     options
         Other options to control the meshing procedure of Gmsh. See
-        http://geuz.org/gmsh/doc/texinfo/gmsh.html#Command_002dline-options for all available
+        https://gmsh.info/doc/texinfo/gmsh.html#Command_002dline-options for all available
         options.
     refinement_steps
         Number of refinement steps to do after the initial meshing.
@@ -64,7 +64,7 @@ def discretize_gmsh(domain_description=None, geo_file=None, geo_file_path=None,
         version = subprocess.check_output(['gmsh', '--version'], stderr=subprocess.STDOUT, env=env).decode()
     except (subprocess.CalledProcessError, OSError):
         raise GmshMissing('Could not find Gmsh.'
-                          ' Please ensure that the gmsh binary (http://geuz.org/gmsh/) is in your PATH.')
+                          ' Please ensure that the gmsh binary (https://gmsh.info/) is in your PATH.')
 
     logger.info('Found version ' + version.strip())
 

src/pymordemos/elliptic_unstructured.py

@@ -17,10 +17,9 @@ def main(
     num_points: int = Argument(..., help='The number of points that form the arc of the circular sector.'),
     clscale: float = Argument(..., help='Mesh element size scaling factor.'),
 ):
-    """Solves the Poisson equation in 2D on a circular sector domain of radius 1
-    using an unstructured mesh.
+    """Solves the 2D-Poisson equation on a circular sector of radius 1 with an unstructured mesh.
 
-    Note that Gmsh (http://geuz.org/gmsh/) is required for meshing.
+    Note that Gmsh (https://gmsh.info/) is required for meshing.
     """
     problem = StationaryProblem(
         domain=CircularSectorDomain(angle, radius=1, num_points=num_points),