[SCons] Remove unused 'rpfont' configuration variable

SConstruct

@@ -586,11 +586,6 @@ config_options = [
            NOTE: Matlab comes with a stripped-down version of 'dot'. If 'dot'
            is on your path, make sure it is not the Matlab version!""",
         '', PathVariable.PathAccept),
-    ('rpfont',
-     """The font to use in reaction path diagrams. This must be a font
-        name recognized by the 'dot' program. On linux systems, this
-        should be lowercase 'helvetica'.""",
-     'Helvetica'),
     ('cantera_version', '', '2.2a')
 ]
 
@@ -1156,8 +1151,6 @@ cdefine('LAPACK_FTN_STRING_LEN_AT_END', 'lapack_ftn_string_len_at_end')
 cdefine('LAPACK_FTN_TRAILING_UNDERSCORE', 'lapack_ftn_trailing_underscore')
 cdefine('FTN_TRAILING_UNDERSCORE', 'lapack_ftn_trailing_underscore')
 cdefine('LAPACK_NAMES_LOWERCASE', 'lapack_names', 'lower')
-
-configh['RXNPATH_FONT'] = quoted(env['rpfont'])
 cdefine('THREAD_SAFE_CANTERA', 'build_thread_safe')
 
 if not env['HAS_MATH_H_ERF']:

include/cantera/base/config.h.in

@@ -69,9 +69,6 @@ typedef  int          ftnlen;       // Fortran hidden string length type
 // with a native compiler
 %(SOLARIS)s
 
-//--------- Fonts for reaction path diagrams ----------------------
-%(RXNPATH_FONT)s
-
 //---------- C++ Compiler Variations ------------------------------
 
 // This define is needed to account for the variability for how

src/kinetics/ReactionPath.cpp

@@ -84,7 +84,7 @@ ReactionPathDiagram::ReactionPathDiagram()
     normal_color = "steelblue";
     dashed_color = "gray";
     dot_options = "center=1;";
-    m_font = "Helvetica"; // RXNPATH_FONT;
+    m_font = "Helvetica";
     bold_min = 0.2;
     dashed_max = 0.0;
     label_min = 0.0;