Fix CMake if() command spacing

c++/src/CMakeLists.txt

@@ -7,15 +7,15 @@ if(BUILD_TESTING)
   if(EXTERNAL_CAPNP)
     # Setup CAPNP_GENERATE_CPP for compiling test schemas
     find_package(CapnProto CONFIG QUIET)
-    if (NOT CapnProto_FOUND)
+    if(NOT CapnProto_FOUND)
       # No working installation of Cap'n Proto found, so fall back to searching the environment.
       #
       # We search for the external capnp compiler binaries via $CAPNP, $CAPNPC_CXX, and
       # find_program(). find_program() will use various paths in its search, among them
       # ${CMAKE_PREFIX_PATH}/bin and $PATH.
 
-      if (NOT CAPNP_EXECUTABLE)
-        if (DEFINED ENV{CAPNP})
+      if(NOT CAPNP_EXECUTABLE)
+        if(DEFINED ENV{CAPNP})
           set(CAPNP_EXECUTABLE "$ENV{CAPNP}")
         else()
           find_program(CAPNP_EXECUTABLE capnp)
@@ -23,7 +23,7 @@ if(BUILD_TESTING)
       endif()
 
       if(NOT CAPNPC_CXX_EXECUTABLE)
-        if (DEFINED ENV{CAPNPC_CXX})
+        if(DEFINED ENV{CAPNPC_CXX})
           set(CAPNPC_CXX_EXECUTABLE "$ENV{CAPNPC_CXX}")
         else()
           # Also search in the same directory that `capnp` was found in