[PL] Added warning messages

The additional warning messages tell that only the Picard non-linear
solver will use additional optimization settings.

ProcessLib/ComponentTransport/ComponentTransportProcess.cpp

@@ -78,6 +78,14 @@ ComponentTransportProcess::ComponentTransportProcess(
             "the conditions for the correct use of this feature are met! "
             "Otherwise OGS might compute garbage without being recognized. "
             "There is no safety net!");
+
+        WARN(
+            "You specified that the ComponentTransport linear solver will do "
+            "the compute() step only upon timestep change. This option will "
+            "only be used by the Picard non-linear solver. The Newton-Raphson "
+            "non-linear solver will silently ignore this setting, i.e., it "
+            "won't do any harm, there, but you won't observe the speedup you "
+            "probably expect.");
     }
 
     _residua.push_back(MeshLib::getOrCreateMeshProperty<double>(

ProcessLib/HeatConduction/HeatConductionProcess.cpp

@@ -60,6 +60,14 @@ HeatConductionProcess::HeatConductionProcess(
             "the conditions for the correct use of this feature are met! "
             "Otherwise OGS might compute garbage without being recognized. "
             "There is no safety net!");
+
+        WARN(
+            "You specified that the HeatConduction linear solver will do "
+            "the compute() step only upon timestep change. This option will "
+            "only be used by the Picard non-linear solver. The Newton-Raphson "
+            "non-linear solver will silently ignore this setting, i.e., it "
+            "won't do any harm, there, but you won't observe the speedup you "
+            "probably expect.");
     }
 
     _heat_flux = MeshLib::getOrCreateMeshProperty<double>(