python plugins: do not build for solaris

The current way to detect the python build parameter leads to

  CC: error: unrecognized command line option '-KPIC'; did you mean '-fPIC'?

  Probably that would be solved when using the sunpro compiler, but that
  caused other problems.

core/cmake/BareosFindAllLibraries.cmake

@@ -50,14 +50,12 @@ else()
       set(Python2_LIBRARIES ${PYTHON_LIBRARIES})
       set(Python2_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS})
       set(Python2_EXECUTABLE ${PYTHON_EXECUTABLE})
-      set(Python2_SITLIB ${PYTHON_SITLIB})
 
     elseif(PYTHON_VERSION_MAJOR EQUAL 3)
       set(Python3_FOUND ${PYTHONLIBS_FOUND})
       set(Python3_LIBRARIES ${PYTHON_LIBRARIES})
       set(Python3_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS})
       set(Python3_EXECUTABLE ${PYTHON_EXECUTABLE})
-      set(Python3_SITLIB ${PYTHON_SITLIB})
     endif()
 
     set(Python_ADDITIONAL_VERSIONS 3.6 3.7 3.8 3.9)
@@ -70,13 +68,11 @@ else()
       set(Python2_LIBRARIES ${PYTHON_LIBRARIES})
       set(Python2_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS})
       set(Python2_EXECUTABLE ${PYTHON_EXECUTABLE})
-      set(Python2_SITLIB ${PYTHON_SITLIB})
-    elseif (PYTHON_VERSION_MAJOR EQUAL 3)
+    elseif(PYTHON_VERSION_MAJOR EQUAL 3)
       set(Python3_FOUND ${PYTHONLIBS_FOUND})
       set(Python3_LIBRARIES ${PYTHON_LIBRARIES})
       set(Python3_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS})
       set(Python3_EXECUTABLE ${PYTHON_EXECUTABLE})
-      set(Python3_SITLIB ${PYTHON_SITLIB})
     endif()
 
   else()
@@ -121,14 +117,6 @@ else()
     )
     include(${CMAKE_CURRENT_BINARY_DIR}/py3settings.cmake)
   endif()
-
-else() # windows
-    set(HAVE_PYTHON 1)
-    set(Python2_FOUND 1)
-    set(Python2_EXT_SUFFIX ".dll")
-
-    set(Python3_FOUND 1)
-    set(Python3_EXT_SUFFIX ".pyd")
 endif()
 
 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Windows")