Update exputil/SLGridMP2.cc

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: The9Cat

exputil/SLGridMP2.cc

@@ -1849,11 +1849,11 @@ class IsothermalSlab : public SlabModel
 
   std::string psa =
     "----     IsothermalSlab NOW uses the traditional density profile proportional to sech^2(z/2H).\n"
-    "----     If you are using the old profile proportional to sech(z/H), please update your model\n"
+    "----     If you are using the old profile proportional to sech^2(z/H), please update your model\n"
     "----     to use the new profile and set the scale height H to be half of the old value.  This\n"
     "----     will ensure that your model has the same density profile and potential as before, but\n"
     "----     with a more standard functional form.  If you have any questions or concerns about\n"
-    "----     this change, please contact the developers on GitHUB.";
+    "----     this change, please contact the developers on GitHub.";
 
 public: