doc: install with almost update

user-doc/Installation.txt

@@ -399,7 +399,7 @@ ALMOST 2.1 can be found in branches/almost-2.1/ and can be compiled:
 \warning ALMOST needs SQLITE3, GZIP and BZIP2 installed on your computer.
 
 \verbatim
-> ./configure --prefix="wherever you want it" 
+> ./configure --prefix="wherever you want it" CXXFLAGS="-O3 -fPIC" CFLAGS="-O3 -fPIC" 
 > make
 > make install
 \endverbatim
@@ -410,8 +410,8 @@ Once ALMOST is installed, PLUMED 2 can then be configured with ALMOST enabled:
 
 \verbatim
 > ./configure --enable-almost CPPFLAGS="-I/ALMOST_INSTALL_PATH/include \
-  -I/ALMOST_INSTALL_PATH/include/almost" LDFLAGS="-L/ALMOST_INSTALL_PATH/lib" \
-  CXXFLAGS="-O3 -fPIC" CFLAGS="-O3 -fPIC"
+  -I/ALMOST_INSTALL_PATH/include/almost" LDFLAGS="-L/ALMOST_INSTALL_PATH/lib"
+  
 \endverbatim
 with ALMOST_INSTALL_PATH set to the full path to the ALMOST installation folder.